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DARWINISM AND HOMAN LIFE 





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DARWINISM AND 
HUMAN LIFE 


BY 


. 
J. ARTHUR THOMSON, M.A., LL.D 


Regius Professor of Natural History in the University of Aberdeen 


AUTHOR OF ‘“‘THE STUDY OF ANIMAL LIFE,” ‘‘THE SCIENCE OF LIFE,” 

‘* OUTLINES OF ZOOLOGY,” ‘‘ HEREDITY,” ‘‘THE BIOLOGY OF THE SEASONS.” 

‘*THE WONDER OF LIFE,” ‘‘ INTRODUCTION TO SCIENCE,” ETC.3 JOINT 
AUTHOR OF ‘‘ THE EVOLUTION OF SEX,” “‘ EVOLUTION,” “SEX” 


NEW EDITION, ENLARGED 


WITH 


Intustrations By E, L. SHinnte 





NEW YORK 
HENRY HOLT AND COMPANY 
LONDON: ANDREW MELROSE, LTD. 
1917 


PRINTED IN GREAT BRITAIN BY 
HAZELL, WATSON AND VINEY, LP. 
LONDON AND AYLESBURY. 


PREFACE TO THE THIRD EDITION 


THE chief aim of this book is to serve as an intro- 
duction to the study of organic evolution, and to 
show how closely “ Darwinism ”’ touches human 
life, both in everyday affairs and in the conflict of 
nations. It has become clear to many that a mis- 
interpretation of Darwinism, notably of the struggle 
for existence and the process of natural selection, 
has been fraught with calamitous evil to civilisa- 
tion ; in these pages an attempt has been made to 
get back to Darwin’s accuracy. The basis of the 
book consisted of six lectures delivered in South 
Africa at the time of Darwin’s Centenary. Their 
endeavour was to explain with thoroughness, and 
yet without technicality, the gist of Darwinism— 
what problems Darwin set himself to solve, and 
what solutions he arrived at, and to indicate what 
progress has been made as regards the problems 
of Organic Evolution since Darwin’s day—what 
has been added to Darwinism, what, if anything, 
has been taken away, and, especially, what is now 
being reconsidered. A demand for a third edition 
has afforded opportunity for the incorporation of 
some new facts and ideas—for Evolution-Theory 


happily continues to evolve. 
Vv 





CONTENTS 


CHAPTER I 


WHAT WE OWE TO DARWIN 


Biographical—Darwin’s Books—The Naturalist’s Problems—The 
first Question: What is This ?—The second Question: How does 
This work ?—The third Question: Whence is This ?—The fourth 
Question: How have Present-day Organisms come to be as they 
are ?—Manifoldness of Darwin’s Services—The Web of Life—The 
Struggle for Existence—Variability of Living Creatures—Natural 
Selection—Vindication of the Evolution Idea—The Evolution 
Theory, a Moda] Interpretation—Darwin’s Argument—Comparison 
of Evolution Formula and Gravitation Formula—The Descent and 
the Ascent of Man—Liberation of Intelligence—Ideal of Scientific 
Mood and Method—Characteristics of Scientific Mood: Passion and 
Reverence for Facts—Scientific Caution—Clearness of Vision— 
Sense of Interrelations—Darwin’s Method of Working—Darwin on 
his own Success—Darwin’s Achievements—Co-operating Influences 
—Particular Reasons for Darwin’s Success . . - pp. 3-42 


CHAPTER II 


THE WEB OF LIFE 


Correlation of Organisms as well as Correlation of Organs—What 
the Metaphor of ‘‘ The Web of Life’? suggests—Dependence of Living 
Creatures upon their Surroundings—Nutritive Chains—Nexus 


Vii 


viii CONTENTS 


between Mud and Clear Thinking—Correlation between Catches of 
Mackerel and Amount of Spring Sunshine—Nutritive Chains in the 
Deep Sea—Dependence of one Organism on another for the Con- 
tinuance of the Species-—-Darwin’s Instance of the Connection 
between Cats and Clover—Scattering of Seeds—TInterrelations 
between Freshwater Mussels and Fishes—Life-histories of Parasites 
—Far-reaching Influence of Certain Animals: HEarthworms—Ter- 
mites, or White Ants—The Hand of Life upon the Earth—Practical 
Importance of a Realisation of the Web of Life , e pp. 45-65 


CHAPTER III 
THE STRUGGLE FOR EXISTENCE 


The Idea not so Simple as it seems—The Anthropomorphism of 
the Idea—Difierent Forms of the Struggle for Existence—Struggle 
for Existence in the Plant World—Illustration of the Complexity 
of the Struggle for Existence—Reasons for the Struggle for Existence 
—Results of the Struggle for Existence—Breadth of the Darwinian 
Concept of the Struggle for Existence—The other Side of the 
Struggle for Existence—Mutual Aid—Application of the Concept 
to Human Life ,. = e “ ‘ » ° » pp. 69-94 


CHAPTER IV 
THE RAW MATERIALS OF PROGRESS 


Organic Progress Primarily depends on Variability—Darwin’s 
Position—Progress since Darwin’s Day in Regard to Variation— 
Variations more Abundant than even Darwin supposed—Proportion 
between Frequency and Amount of Variations—Correlation of 
Variations—Brusque Variations more Frequent than was formerly 
supposed—Discontinuous Variations—Mutations—Darwin’s Posi- 
tion in Regard to Mutations—Origin of Variations—Germinal 
Selection—Variational Stimuli—Modifications or Acquired Charac- 
ters—Indirect Importance of Modifications—Modification-Species— 
Individual Plasticity—Relation to Human Life - pp. 97-12¢ 


CONTENTS 1X 


CHAPTER V 


FACTS OF INHERITANCE 


Progress during the Darwinian Era—Demonstration of Heritable 
Qualities—Heredity, a Term for the Genetic Relation between 
Successive Generations—Appreciation of Distinction between 
Nature and Nurture—The Idea of the Continuity of Generations— 
Critical Attitude in Regard to Various Conclusions—Mendelism— 
Methods of Studying Heredity—Microscopical Study of the Germ- 
cells—Statistical Study: Filial Regression—Galton’s Law of 
Ancestral Inheritance—Experimental Study—Pairing of Similar 
Pure-bred Forms—Blending—Particulate Inheritance—Exclusive 
Inheritance—Reversion—New Departures—Mendelian Inheritance 
—Unit Characters—The Case of Andalusian Fowls—Waltzing Mice 
—Occurrence of Mendelian Inheritance—Practical Importance of 
Mendelism—Much Progress but Great Uncertainty—Transmission 
of Acquired Characters—Disease—Facits and _ Possibilities—A 
Striking Case—Logical Position of the Question—Cases where 
the Theory of Modification-inheritance is Inapplicable—Im- 
portance of Environment and Function Remains—Selection and 
Stimulus—Indirect Importance of Modifications—Practical Im- 
port of the Question as to the Transmission of Acquired 
Characters—Inheritance of Moral Character—Three General 
Conclusions ° . ° ° ° ° © pp. 129-177 


CHAPTER VI 
SELECTION : ORGANIC AND SOCIAL 


Influence of Malthus—Darwin’s Position—The Theory stated— 
The Theory of Natural Selection to be tested as an Interpretative 
Formula—lIllustrations of Natural Selection—Objections and 
Criticisms—Adaptations—Changes since Darwin’s Day—Evidences 
of Natural Selection—Lessening the Burden of the Theory—Sexual] 
Selection—Isolation—Gradual Diminution of Natural Selection in 


x CONTENTS 


Mankind—Contrast between the Human Race and the Animal 
World—Some Natural Selection persists in Mankind—The Dilemma 
of Civilisation—The extreme laissez-faire Position—Social Surgery 
—Is Social Selection compensating for Diminished Natural Selec- 
tion ?—Reversed Selection in Human Society—Practical Considera- 
tions—Summary of the General Argument in regard to Human 
Selection—Constructive Suggestions—Selection of Eutopias— 
Selection of Healthful Occupations—Eugenic Selection 

pp. 181-249 


REPRESENTATIVE BOOKS ON DARWINISM . pp. 253-258 


PLATE 


I. 


ia: 


HEE 


4 


a 
XII. 


LIST OF ILLUSTRATIONS 


(Drawn BY Miss EK. L. SHINNIE) 


FACING PAGE 


DoMESTICATED Racks oF Pigeons EVOLVED 
FROM Rock DovE : ; : ’ , 


DIAGRAMMATIC GENEALOGICAL TREE OF ANIMALS 


NUTRITIVE CHains: MACKEREL, CoPpEpops, IN- 
FUSORIANS, AND DIATOMS 


INTER-RELATIONS : Cats, VOLES, HUMBLE-BEEs, 
PURPLE CLOVER . A - j ; : 


Lire History oF THE Common FRoG : ; 
EXAMPLES OF VARIATIONS tM : 


VARIATIONS OF THE SHELL OF GARDEN SNAIL 
(AFTER Lane) . : : : : : 


GERM-CELLS ° e e ® e ° ° 


MENDELIAN INHERITANCE IN GUINEA Pics (AFTER 
CASTLE Wee : : : 


MENDELIAN INHERITANCE IN ANDALUSIAN Fow.L 
(AFTER DARBISHIRE) . : : : : 


EXAMPLES OF SEX DIMORPHISM A “ 


EARLY STAGES AND LATE STAGES IN EVOLUTION- 
SERIES ‘ . “ : i A “ 


22 
36 


50 


52 
80 
106 


112 
138 


148 


152 
208 


212 


a aah ‘ 
hy wt * 





CHAPTER I 
WHAT WE OWE TO DARWIN 





CHAPTER I 


WHAT WE OWE TO DARWIN 


Biographical—Darwin’s Books—The Naturalist’s Problems—The 
first Question: What is This ?—The second Question: How 
does This work ?—The third Question: Whence is This ? 
—The fourth Question: How have Present-day Organisms 
come to be as they are ?—Manifoldness of Darwin’s Services 
—The Web of Life—The Struggle for Existence—Variability 
of Living Creatures—Natural Selection—Vindication of the 
Evolution Idea—The Evolution Theory, a Model Interpreta- 
tion—Darwin’s Argument—Comparison of Evolution Formula 
and Gravitation Formula—The Descent and the Ascent of 
Man—Liberation of Intelligence—Ideal of Scientific Mood 
and Method—Characteristics of Scientific Mood: Passion and 
Reverence for Facts—Scientific Caution—Clearness of Vision 
—Sense of Interrelations—Darwin’s Method of Working— 
Darwin on his own Success—Darwin’s Achievements—Co- 
operating Influences—Particular Reasons for Darwin’s Success. 


BrocrapruicaL.—Charles Darwin, the greatest natu- 
ralist who has yet lived, was born at Shrewsbury 
on February 12, 1809, on the same day as Abraham 
Lincoln. Indeed the year was one of remarkable 
children, for it saw the birth of Tennyson and 
Gladstone, of Chopin and Mendelssohn, of Mrs. 
Browning and Fanny Kemble, of Edgar Allan 
Poe and John Hill Burton, of Edward Fitzgerald 
and Oliver Wendell Holmes, and many more. We 
shall not compare Darwin with any of the 
illustrious personalities whom we have named, 
for the comparison of Incommensurables is always 
unprofitable; but without exaggeration, which 
3 


4 DARWINISM AND HUMAN LIFE 


should be absent from scientific discourse, it may 
be said that no other man of science has influenced 
the framework of human thought as Darwin has 
done. We propose, first of all, to recall very briefly 
the leading facts of his life. 

Darwin’s inheritance must have given him a 
scientific bent. His grandfather, Krasmus Darwin, 
the author of “‘ Zoonomia ”’ (1794), was a thoughtful 
evolutionist ; his father, Robert Waring Darwin, 
also a physician, had an unusually keen faculty 
of observation; his mother was a daughter of 
Josiah Wedgwood, the founder of the famous 
pottery works; and it may be further noted that 
Sir Francis Galton was Darwin’s cousin. In addi- 
tion to actual inheritance, there was another 
influence which would tend to direct Darwin’s 
mind towards science, namely, the scientific atmo- 
sphere and tradition of his home. 

As a boy Darwin was strong and active; he 
was fond of open-air life, and he made nothing 
of the classical school to which he was sent. In 
1825 he went with his brother to Edinburgh with 
the purpose of studying medicine; but he found 
the lectures “intolerably dull”? and made little 
of them. He got to know several naturalists, 
however, and made his first discovery—in regard 
to the development of the sea-mat (Flustra). After 
two sessions at Edinburgh he went to Cambridge 
with the vague view of becoming a clergyman; but 
of this period he writes: “ During the three years 
which I spent at Cambridge my time was wasted, 
so far as academical studies were concerned, as 
completely as at Edinburgh and at school.” 

During his stay at Cambridge he kept up his 
boyish beetle-collecting and indulged his fondness 


WHAT WE OWE TO DARWIN 5 


for riding and shooting. He came under the 
influence of Professor Henslow, the botanist, who 
advised him to read Lyell’s “Principles of 
Geology,” and was instrumental in sending him 
off on the Beagle. 

Of the Beagle voyage, which extended for five 
years (1831-6), mainly spent along the coasts of 
South America, Darwin says: “ This was by far the 
most important event in my life, and has deter- 
mined my whole career.” He learned to work 
hard, he accumulated a wealth of impressions, and 
he had time to think. On one of his land journeys 
over the Pampas he was struck by the resemblances 
between living and extinct forms, and wrote : “ This 
wonderful relationship in the same continent 
between the dead and the living will, I do not 
doubt, hereafter throw more light on the appearance 
of organic beings on our earth, and their dis- 
appearance from it, than any other class of facts.” 
The savage character of the natives at Tierra del 
Fuego and the individuality of the fauna on the 
various Galapagos islands were seed-impressions 
which afterwards bore fruit in thought. 

For six years after returning from the Beagle 
voyage, Darwin worked in London at his collections, 
especially at the geological specimens. He pub- 
lished his “ Naturalist’s Voyage ” in 1839, and in 
the same year married his cousin, Emma Wedg- 
wood. As his health had not been good after his 
return from the Beagle, he left London in 1842, 
and settled in a country house at Down. There 
in quiet industry, badly hampered by ill health, 
he spent the rest of his life. He died on April 19, 
1882, one of the great Immortals among men. 

Darwin’s Booxs.—The forty years at Down 


6 DARWINISM AND HUMAN LIFE 


were punctuated by the completion of book after 
book—the “ milestones of my life,” as he called 
them; and it may be useful to note that Darwin 
recognised three stages in his career as a biologist: 
(1) the mere collector at Cambridge; (2) the 
collector and observer on the Beagle voyage (to 
which he thought he owed “ the first real training 
and education ’”’ of his mind); and (3) the trained 
naturalist after his eight years’ work on barnacles. 

His books may be arranged in three groups: 

(a) The early zoological and geological studies, 
e.g. ““ Zoology and Geology of the Beagle ” (1840- 
46), “Coral Reefs ” (1842), “Monograph on the 
Cirripedia *” (1846-54). Although the book on 
Earthworms was not published till 1881, it was 
begun more than forty years before, and may be 
included in the first series. 

(6) The series of evolutionary volumes: “ The 
Origin of Species’ (1859); “ Variation of Ani- 
mals and Plants under Domestication ”’ (1868) ; 
“Descent of Man” (1871); *“ Expression of the 
Emotions ” (1872). 

(c) The botanical books—largely influenced by 
evolutionary ideas: “ Fertilisation of Orchids ” 
(1862); “Movements and Habits of Climbing 
Plants ” (1875); “* Insectivorous Plants 7” (1875) ; 
“ Cross and Self-fertilisation in Plants” (1876) ; 
“ The Different Forms of Flowers in Plants of the 
same Species ” (1877); “ The Power of Movement 
in Plants ” (1880). 

THE NatTuRAuist’s PRoBLEMS.—It may be useful 
to inquire into the aims and methods of naturalists 
in general, if we are rightly to appreciate the 
services rendered by the greatest of them all. The 
problems appear at first sight to be numerous and 


WHAT WE OWE TO DARWIN 7 


varied, but, from a certain distance, we see that 
naturalists ask only four questions: What is this 
living creature? How does it work? Whence 
has it arisen? How has it come to be as it 
is? Darwin asked each of these questions, but, 
after serving his apprenticeship in answering the 
first three—for he was anatomist, physiologist, 
and paleontologist in turn—he settled down to 
the fourth—the question of questions—How have 
living creatures come to be as they are ? | 

The Question What rs This?—The naturalist’s 
first question—however learnedly he may phrase 
it—is one of the child’s first questions, asked long 
before it can speak: “ What is this?’ In how 
many different tones—of fear, of awe, of wonder, 
of inquisitiveness—has this question been asked 
since man and science began! Was it not 
Aristotle’s question when a new specimen was 
brought to him? Was it not the question of 
the naturalist on the Challenger when the dredge 
came up? Is it not the question on the lips of 
every teacher and student of natural history 
to-day ?—What is this? It is a “simple ques- 
tion,’ but how hard to answer, as we press it 
further and further home, from external features 
to internal structure, from organs to tissues, from 
tissues to cells, as we put one lens after another in 
front of our own, as we call to our aid all sorts 
of devices—scalpel and forceps, razor and micro- 
tome, fixative and stain! ‘“ What is this,’ we 
say, “in itself and in all its parts ? what is this by 
itself and when compared with its fellows and 
kindred ? *’, and our answer broadens and deepens 
till it furnishes the raw materials of the science of 
morphology. 


8 DARWINISM AND HUMAN LIFE 


The Question How does This work ?2—But close 
upon the first question—What is this ? there rises a 
second—How does this work? It 1s equally natural 
and necessary, and throughout the progressive 
periods in the history of biology the two questions 
have never been far apart. They have evolved 
together especially during the last hundred years, 
prompting one another to a more and more pene- 
trating inquisitiveness. The key-word of the one 
is structure, or organisation ; of the other function, 
or activity. The creature which our first question 
killed and picked to pieces has to be put together 
again and made to work. What does it do? how 
does it do it? how does it go? how does it keep 
a-going ? how does it set other creatures like itself 
a-going ? how long can it go ? how does it cease 
from going? In other words, how does the 
organism feel and move ? how does it grow and 
multiply ? how does it waste, recover itself, and 
finally, in most cases, die? Above all, what 
is the secret of its activity and of its power of 
effective response to the order of nature? These 
are some of the physiological problems which 
recall Clerk Maxwell’s boyish question—‘‘ What is 
the go of this—the particular go of this ?” 

The Question Whence is This ?—A third question 
is—Whence is this? and, though it 1s probably 
as ancient as the others, the answering of it is 
distinctly modern. It is really a double question, 
for we may inquire into the development—the 
becoming—of the individual, and we may in- 
quire into the history of the race to which the 
individual belongs. We may study the child- 
animal in its cradle—the bee-grub in the comb, 
the embryo skate in its mermaid’s purse, the 


WHAT WE OWE TO DARWIN 9 


chick within the egg-shell—and the answer to the 
question—Whence came this individual animal 
as a whole and in each of its parts ? is embryology. 
On the other hand, we may study the history of 
the race as it is hidden in the strange graveyards 
of the buried past, the fossil-bearmg rocks, and 
the answer to the question—Whence came this 
race ? is paleontology. 

The Question How have Present-day Organisms 
come to be as they are?—There remains a fourth 
question, also ancient, but since Darwin’s day 
asked with a new hopefulness—How have these 
living creatures come to be as they are? They have 
had a history—a slow racial evolution—as surely 
as they have an individual development. We 
have got a firm grasp of the modal theory—that 
the present is the child of the past, but the causal 
theory is still being evolved. The idea of evolution 
is the most potent thought-economising formula 
which the world has yet known, but as to the 
factors in evolution we are still only inquiring. 
What are the originative and what the directive 
factors ? How has the raw material of progress, 
which we call variation, been made available 
throughout the countless ages ? and how has this 
raw material been fashioned to shape and use ? 

MANIFOLDNESS OF DaRWIN’s SERVICES.— What 
do we owe to Darwin? It is the meed of greatness 
to receive manifold tribute. J’or how many diverse 
reasons has Shakespeare the world’s homage! A 
great life-work is like a great picture ; this character 
appeals to me and that to you. So some say that 
what we most owe to Darwin is our evolutionist out- 
look, while others emphasise the idea of selection, 
and others the demonstration that the problems 


10 DARWINISM AND HUMAN LIFE 


of heredity and variation are amenable to 
scientific analysis, and others that he first clearly 
showed the affiliation of man to the rest of creation. 
The fact is that Darwin focussed so many ideas 
that were previously dim, and made so many old 
facts new, and gave us keys to so many doors, that 
it is a matter of opinion which of his services was 
greatest. This, at least, is certain: that, when 
we have thought for an hour of what we owe to 
Darwin, we shall not have discovered how much 
that is. For his intellectual legacy is still earning 
interest and increasing*our wealth. His leaven 
will go on fermenting till the whole is leavened. 
Then it will be time for a new yeast. 

(1) Taz Wes or Lire.—What do we owe to 
Darwin? We give precedence to Darwin’s picture 
of “The Web of Life,” the service that appeals 
most to the naturalist, to whom the conception is 
absolutely fundamental. It les below the idea of 
the Struggle for Existence, and therefore below the 
idea of Natural Selection. It is a fact of life which 
will remain, however theories may change. It 
is a fine idea to dream over and to work with. 

What is meant by Darwin’s picture of the Web 
of Life, and where did he paint it? We find it 
in all his works—a luminous background—the 
idea of linkages in nature, the idea of the corre- 
lation of organisms. Cats have to do with the 
clover crop, Darwin says, and earthworms with 
the world’s bread supply. If there is an orchid in 
Madagascar with a spur eleven inches long, Darwin 
prophesies that there is a moth with a proboscis 
of equal length. No bird falls to the ground 
without sending a throb through a wide circle, for 
Darwin rears eighty seedlings from a single clod 


WHAT WE OWE TO DARWIN 1] 


taken from a bird’s foot. Long nutritive chains 
bind the bracken on the hill-side to the brain 
of the proprietor—if he is fond of eating trout. 
The patent-leather shoes on his feet connect him 
with the melancholy slaughter of seals, while 
his ivory-backed toilet-brushes implicate him in 
the passing of the elephant. ‘There is a ceaseless 
circulation of matter and energy. All things 
flow. Influence passes from A. to Z., though 
Z. is quite unaware of A. What ripples spread 
and spread from the introduction of rabbits into 
Australia, or of sparrows into the United States, 
or of the mongoose into Jamaica! What abso- 
lutely essential connections there are between 
cutting down trees and a plague of insects, between 
birds and seed-scattering, between sunlight and 
the catches of mackerel ! 

Take an instance from “ The Origin of Species” : 
“If certain insectivorous birds were to decrease 
in Paraguay, the parasitic insects would probably 
increase; and this would lessen the number of 
navel-frequenting flies—then cattle and _ horses 
would become feral, and this would certainly 
greatly alter (as indeed I have observed in parts of 
South America) the vegetation ; this, again, would 
largely affect the insects ; and this, as we have just 
seen in Staffordshire, the insectivorous birds, and 
so onwards in ever-increasing circles of complexity.” 

(II) Tue Strueeie ror Existence.—What do 
we owe to Darwin? In the second place, we may 
rank his realisation of “the struggle for exist- 
ence.” From Aristotle to Lucretius, from Buffon 
to Robert Chambers, there had been allusion to 
the struggle for existence in nature, and every one 
knows, for instance, how it recurs repeatedly in 


12 DARWINISM AND HUMAN LIFE 


Tennyson’s “In Memoriam,” which was written 
before ‘ The Origin of Species.” The poet speaks 
of Nature “red in tooth and claw with ravine ” ; 
“so careless of the single life’; “of fifty,” or 
(as he afterwards suggested) “of myriad seeds 
she often brings but one to bear.” But itis certain 
that no one before Darwin realised the length 
and breadth, the height and depth, of the struggle 
for existence. His realisation of it is “ bigger ” 
than that of most of his successors. Darwin 
recognised the struggle between Fellows, the 
struggle between Foes, and the struggle be- 
tween Living Creatures and the Physical Forces. 
(A) There is cannibalism in the cradle in the 
ego-capsules of the buckie and the dog-whelk ; 
locust may eat locust when the worst comes to 
the worst; stag may fight to the death with 
stag in the forest clearing; certain mountain- 
varieties of sheep will starve out other mountain- 
varieties; the sister seedlings compete together 
in the plot: that is Struggle between Fellows. We 
may extend this category of competition between 
individuals of the same species to include com- 
petition between individuals of nearly related 
species, though what is involved in the step should 
be carefully noticed. If we make the extension, 
however, we include Darwin’s well-known case 
of brown rat versus black rat. The other illus- 
trations he gave concerned two kinds of thrush, 
two kinds of swallow, two kinds of cockroach, and 
two kinds of charlock. (B) Secondly, the world 
is full of competition and struggle between living 
creatures not nearly related to one another— 
between fox and hare, between stoat and rabbit, 
between mongoose and snake, and s0 on, end- 


WHAT WE OWE TO DARWIN 13 


lessly: that is Struggle between Foes. The foes 
do not need to be well matched. Alfred Russel 
Wallace has recently told us of a pair of blue tits, 
with a large family, who worked for sixteen hours 
a day at midsummer, and it was estimated that 
they captured in that time about two thousand 
caterpillars and grubs. A locust-bird at work is 
another good instance of a one-sided struggle. 
Nor do the foes need to compete directly—it will 
suffice if both seek the same food, the same locality, 
the same anything. (c) Darwin recognised a 
third great mode of the struggle for existence 
when he spoke, for instance, of a plant on the 
edge of the desert struggling for life against the 
drought, and of the birds struggling against the 
winter. This is the Struggle with Fate. 

As a number of illustrious living naturalists 
persist in maintaining that what Darwin mainly 
thought of was the struggle between near kin— 
for room in the nest, for food at the platter, 
for foothold on the rock, and so on, we must 
remember Darwin’s emphatic statement that he 
used the term “in a large and metaphorical 
sense.’ He speaks of two “carine animals”’ 
struggling with each other in a time of dearth; 
of mistletoe versus mistletoe on the same branch ; 
of mistletoe versus other fruit-bearing plants ; 
of a plant on the edge of the desert in days of 
drought ; and then says, “ In these several senses, 
which pass into each other, I use, for convenience’ 
sake, the general term of Struggle for Existence.” 
The fact is that the “ struggle for existence” is a 
formula-phrase including all the reactions and 
endeavours of living creatures in face of difficulties 
and limitations. 


14 DARWINISM AND HUMAN LIFE 


(IIT) Vartapiniry or Living Creatures.—What 
do we owe to Darwin? A. vivid presentation of 
the idea of variability, or organic flux. There had 
been, of course, transformists before his day, but 
either they had not the idea very clearly in their 
own minds or they failed in making it convincing 
to others. So it was that Darwin had to make 
way against the general conviction of contemporary 
naturalists that species were fixed. In 1844 he 
wrote to Hooker: ‘I am almost convinced ... 
that species are not (it is like confessing a murder) 
immutable.” The idea seems to have suggested 
itself more than once on the Beagle voyage ; for 
instance, when he found fossils in Argentina very 
like living forms and yet different. | 

In forming his impression of the variability of 
living creatures Darwin depended on what has 
taken place in domestication and cultivation, 
on the experience gained in his systematic work 
that specific characters are far from being constant, 
and that so-called varieties often link species to 
species. A species is a group of similar individuals 
of common descent, capable of pairing together, 
and breeding more or less true. It may be repre- 
sented by a constellation of dots, densest towards 
the centre (which means that the great majority 
are very like one another) and thinning out to- 
wards the periphery where the variants extend 
as outliers in different directions. When we 
begin to study a corner of the zoological sky it 
seems to be covered with very distinct constella- 
tions, and it is all clear; but a many cases deeper 
study shows that one constellation is connected 
with another by outliers, and that there is con- 
tinual flux. 


WHAT WE OWE TO DARWIN 15 


Darwin recognised the occurrence of structural 
changes directly due to changed surroundings 
and changed habits, which he called “ definite 
variations,’ which are now usually called modi- 
fications, or “acquired characters’; and he believed 
that these were, in some cases, transmitted. This 
is the characteristic Lamarckian position. But the 
raw materials of progress which Darwin chiefly 
relied on were what he called the “‘ numerous, stc- 
cessive, slight, favourable variations ” (‘ Origin of 
Species,” p. 421). He also took account of “sudden 
and considerable deviations of structure ’’—“ single 
or occasional variations,” as he called them; but 
he very deliberately refrained from attaching 
importance to such leaps and bounds, thinking 
that they had no staying power in inheritance. 
As to the causes of the inborn variations in living 
creatures, Darwin had no lght, and, with his 
characteristic candour, said so. 

(IV) Naturat SEeLEotiIon.—What do we owe 
to Darwin? The theory of Natural Selection, 
which his magnanimous fellow-worker, Alfred 
Russel Wallace, independently stated at the same 
time (1858), and of which there had been a few 
previous suggestions of a more or less vague de- 
scription. It was here that Darwin’s originality 
was gteatest, for he revealed the many different 
forms—often very subtle—which Natural Selection 
takes, and, with the insight of a disciplined scientific 
imagination, he realised what a mighty engine of 
progress it has been and is. His theory is simple 
and admits of brief statement. We can under- 
stand Huxley’s remark: ‘“ How extremely stupid 
not to have thought of that!” 

(1) Variability is a fact of life. The members of 


16 DARWINISM AND HUMAN LIFE 


a family or of a species are not born alike: some 
have qualities which give them a little advantage 
both as to hunger and as to love; others are 
relatively handicapped. We may not understand 
their origin, but we know that useful variations 
occur. 

(2) A struggle for existence is also a fact of 
hfe—a struggle for existence in an_ intricate 
web of interrelations. It operates whenever there 
is disturbance of equilibrium or clashing of inter- 
ests, whenever the living creature makes effective 
responses to the limitations closing in upon it. 

(3) In certain forms of the struggle for existence 
the relatively less fit forms are eliminated, which 
does not necessarily mean that they come at 
once to a violent end, but often simply that they 
die before the average time and are less successful 
than their neighbours as regards their offspring. 
The result is that the relatively more fit tend 
to survive, and to become the majority. The fit- 
ness may refer to the whole constitution, or to a 
particular character. 

(4) As many variations are transmitted from 
generation to generation, and may, through the 
pairing of similar or suitable mates, be gradually 
increased in amount, the eliminative or selective 
process, if discriminate, consistent, and sustained, 
will work towards the establishment of new 
adaptations and new species. Natural Selection is 
Nature’s process of singling and sifting for parent- 
hood by the discriminate eliminationof the relatively 
less fit to the given conditions. 

Take, in the meantime, just one illustration. 
In Dublin Bay there is a sandy island, about 
120 years old. It is frequented by a light-coloured 


WHAT WE OWE TO DARWIN Ly 


variety of mouse which burrows in the sand. 
It seems reasonable to interpret the prevalence 
of this inconspicuous sand-coloured variety as 
due to the elimination of the ordinary darker 
mice by birds of prey. 

Wallace asks the interesting question: Why, 
after many had failed, did Darwin and he find 
the same solution of the riddle of progress, namely, 
in Natural Selection? He pomts out that they 
had certain experiences in common: (1) as ardent 
beetle-hunters from their youth up, they were both 
accustomed to study minute details and varieties, 
and they thus had a trained eye for individualities ; 
(2) they both had a speculative turn of mind, and 
were fond of trying solutions ; (3) they both enjoyed 
the wealth of impressions that travel gives, and the 
boon of solitude and quiet in which to “ attend 
their minds unto” the problem that “ haunted ” 
them; and (4) both had read Malthus. Perhaps 
one might add that both had realised the selective 
processes implied in the keen competitive con- 
ditions of their time. 

(V) VINDICATION OF THE EvotuTion IpEA.— 
What do we owe to Darwin? The first successful 
vindication of the evolution idea. It was not 
his own, nor was he its first champion, yet we 
always, and rightly, think of Darwin and the 
Doctrine of Descent together. He made it current 
coin of the intellectual realm. He made the 
nations “ think in terms of evolution.” 

The central idea of evolution is that the present 
is the child of the past and the parent of the 
future. It is the idea of progressive change from 
phase to phase without loss of continuity. A 
process of Becoming leads to a new phase of 


2 


18 DARWINISM AND HUMAN LIFE 


Being—whether in solar systems or in social 
institutions or in living creatures. But in the 
first the continuity is sustained in identity of 
substance, in the second by tradition and social 
registration, and in the third by the hereditary 
linkage of successive generations. 

‘ Stated concretely, in regard to living creatures, 
the general doctrine of descent suggests, as we 
all know, that the plants and animals now around 
us are the results of natural processes working 
throughout the ages; that the forms we see are 
the lineal descendants of ancestors on the whole 
somewhat simpler, that these are descended from 
yet simpler forms, and so on backward, till we 
lose our clue in the unknown—but doubtless 
momentous—vital events of pre-Cambrian ages, 
or, in other words, in the thick mist of life’s 
beginnings.” * 

“As in the development of a fugue,” Samuel 
Butler says, ‘ where, when the subject and counter- 
subject have been announced, there must thence- 
forth be nothing new, and yet all must be new, 
so throughout organic nature—which is a fugue 
developed to great length from a very simple 
subject—everything is linked on to and grows 
out of that which comes next to it in order.” 

The evolution idea is not only essentially simple, 
it is also very ancient. It is as old as Aristotle— 
and older. It is perhaps as old as clear thinking, 
which we may date from the unknown time when 
man discovered the year, with its marvellous 
object-lesson of recurrent sequences, and realised 
that his race had a history. Whatever may have 


1 “ The Study of Animal Life,” by J. Arthur Thomson. (Murray, 
London.) 


WHAT WE OWE TO DARWIN 19 


been its origin, the idea was familiar to several 
of the ancient Greek philosophers, as it was to 
Hume and Kant; it fired the imagination of 
Lucretius and linked him to Goethe; it persisted 
through the ages of other than scientific pre- 
occupation; it became a concrete theory of the 
transformation of species in the hands of the 
pioneers of modern biology—such as Buffon, 
Lamarck, Erasmus Darwin, and Treviranus; and 
it became current intellectual com when Charles 
Darwin, Alfred Russel Wallace, Herbert Spencer, 
Huxley, and Haeckel, with united but varied 
achievements, won the conviction of most thought- 
ful men. 

THe Evotution THeory A Monat INTERPRE- 
TATION.—It must be carefully noted that the 
general idea of organic evolution is a modal inter- 
pretation of the history of the animate world. It 
suggests the mode by which organisms have come 
to be as they are. It says that the mode is scien- 
tifically decipherable, and is comparable to what 
we see going on in the origin of new breeds of 
pigeons or new varieties of wheat. But what 
other view is there? We do not know of any 
other screntific view, and the only alternative is 
to maintain that the mode of origin of the various 
kinds of living creatures is undecipherable scien- 
tifically, and cannot be formulated except in 
transcendental terms, such as Creation. The 
general view when Darwin published the “ Origin 
of Species” was Creationist, or, if the naturalist 
fought shy of such words, the Linnean dogma 
of the Fixity of Species was accepted and the 
question of origin was regarded as hopeless. 

Much will be gained if we clearly understand 


20 DARWINISM AND HUMAN LIFE 


that the theory of evolution suggests a modal 
interpretation within the scientific universe of 
discourse, while the other view gives up even 
the possibility of scientific re-description, and 
suggests a transcendental formula as alone possible. 
It is quite certain that there is no manner of 
use in pitting a scientific formula against a trans- 
cendental one: that always means a false anti- 
thesis and intellectual fog. They are incom- 
mensurables. The true antithesis is between a 
scientific interpretation and maintaining that it 
is impossible to give one. 

There is an intricate, beautiful, rational pattern 
before us in nature: are we to think of it as woven, 
thread by thread, by invisible hands in a way 
past finding out screntefically; or was there so 
much mind put into the original institution of 
things—an apparently simple loom—that thence- 
forth the web has been worked out automatically 
in a manner that admits of scientific formulation ? 
When we finally discover that the doctrine of 
descent and all the theories of evolution do not 
fundamentally explain what they formulate,’ we 


1 This expresses the modern view that science is re-description 
in “simpler terms ’’—which, however, are not themselves “ ex- 
plained.” The object of science is “ the complete and consistent 
description of the facts of experience in the simplest possible terms.” 
As Prof. Poynting put it, “‘a law of nature explains nothing, it is 
but a descriptive formula.” ‘‘ We explain an event not when 
we know ‘ why’ it happened, but when we know ‘ how’ it is like 
something else happening elsewhere or otherwise—when, in fact, we 
can include it as a case described by some law already set forth. 
The causes that Science seeks after are secondary causes, not 
ultimate causes ; effective causes, not final causes.” But scienti- 
fic description differs from ordinary description in depth, order, 
connectedness, and continuity. See ‘Introduction to Science ” 
(Home University Library), by J. Arthur Thomson. 


WHAT WE OWE TO DARWIN 21 


shall be able, perhaps, to return to the transcen- 
dental formula with intelligence. 

In regard to the proposition that science offers 
not explanations but formulations, it 1s important 
to bear in mind (1) that the biologist, for instance, 
postulates simple living creatures with which to 
start his story of evolution, for he does not know 
how they began; (2) that he takes for granted 
certain primary qualities of living matter, notably 
“irritability ” ; (3) that he does not account, as 
yet, for the “ big lifts’ in evolution, or for the 
general progressiveness, eg. in complexity of 
organisation and freedom of life—the tree having 
grown vertically, so to speak, as well as horizontally; 
and (4) that the biologist’s causal equation is not 
like those of mechanics, where causa aequat effectum. 
Bergson distinguishes (a) a cause acting par 
umpulscon, as when one billiard-ball strikes an- 
other (where the quantity and quality of the 
effect vary with the quantity and quality of 
the cause); (b) a cause acting par delanchement, 
as when a spark makes the powder explode (where 
the invariable effect has no relation to the quantity 
and quality of the cause); and (c) a cause acting 
par deroulement, as when the spring which 
works the gramophone unrolls the tune on the 
cylinder (where the quantity of the effect is pro- 
portionate to the quantity of the cause). In the 
first case only does the cause explain the effect, 
but living is not such an effect. 

Darwin’s ARGUMENT.—What did Darwin really 
do in regard to the general doctrine of organic 
evolution ? He showed that it rationalises our 
whole outlook. He took a wide sweep of things 
as they are and showed that they admit of evo- 


® 


22 DARWINISM AND HUMAN LIFE 


lutionist interpretation. There are no locks which 
its key does not fit. As there is often misunder- 
standing in regard to the so-called “* evidences of 
evolution,” we must note that Darwin’s magistral 
work was not of the nature of an induction leading 
up to the doctrine of descent as its conclusion. 
It was a deductive vindication of the doctrine 
that he gave us—‘a cumulative justification 
showing how well the formula fits a vast series of 
facts.” We cannot agree with the statement 
that Darwin proved in-1859 what Lamarck had 
only suggested fifty years before,* for there is no 
logical proof of the doctrine of descent. It must 
be allowed, however, that Darwin’s illustrations 
what some would call his cumulative evidence— 
were so carefully chosen that they left few openings 
for effective criticism. The basis of fact which 
the formula was shown to fit was solid, broad, and 
representative. 

(a) Darwin pointed to the evolution which is 
going on in domesticated animals, such as sheep 
and cattle, and in cultivated plants, such as 
cabbages and apples, and used the argument: If 
Man has been instrumental in fixing all these 
varieties in a short time, what may not Nature 
have effected in a very long time? This line of 
argument has been greatly strengthened of recent 
years by cases like De Vries’s mutations of the 
Hvening Primrose (Hnothera lamarckiana). 

(6) There is significance in the broad fact that 
it 1s possible to arrange the animal kingdom in 
a provisional genealogical tree, showing stages 
In progressive organisation from lower to higher 





1 Lamarck’s ‘“ Philosophie Zoologique”’ was published in 1809, 
when Darwin was bora. 


PLATE I 





DOMESTICATED RACES OF PIGEONS EVOLVED FROM Rock DOVE. 


1, Wild Rock Dove, Columba livia; 2. Pouter; 3. Owl; 4. Fantail; 5. White 
Jacobin, 


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WHAT WE OWE TO DARWIN 23 


forms. When we take a particular group of 
animals it 1s often possible to draw that branch 
of the genealogical tree with a firmer hand, for 
it is the mutual relations of the large series which 
are so difficult. From the actual classification of 
organisms, from the peculiar way in which the 
categories are related one within the other— 
species, genera, families, orders, classes—we get 
an impression of affiliation which we do not get 
from a classification of rocks or other inanimate 
objects. 

(c) Darwin attached great importance to the 
anatomical evidence of adherence to general type 
in spite of the most manifold diversity in external 
form. If we take, for instance, a series of fore- 
limbs among Vertebrates—the arm of a frog, the 
paddle of a turtle, the wing of a bird, the fore-leg 
of a horse, the flipper of a whale, the wing of a 
bat, the arm of man—we find a detailed homology 
not only as regards the bones, but as regards 
muscles, nerves, and blood-vessels. It is difficult 
to suggest any interpretation except that the 
resemblance is due to relationship. As Darwin 
said: “* How inexplicable is the similar pattern 
of the hand of a man, the foot of a dog, the wing 
of a bat, the flipper of a seal, on the doctrine of 
independent acts of creation! How simply ex- 
plained on the principle of the natural selection 
of successive slight variations in the diverging 
descendants from a single progenitor ! ” 

(d) Darwin made a good case out of rudi- 
mentary or vestigial organs—the dwindling remains 
of structures which were presumably well developed 
in ancestral forms. Cetaceans have no visible 
hind-limbs, but many show relatively small ves- 


24 DARWINISM AND HUMAN LIFE 


tiges buried deep below the surface. The whale- 
bone whale has two sets of teeth which never cut 
the gum, their place being taken by baleen plates. 
The New Zealand Kiwi has minute traces of wings, 
the limbless slow-worm has a rudimentary pectoral 
girdle, man has scores of vestiges, such as the 
third eyelid or the ear-moving muscles. Darwin 
compared these vestiges to the unsounded letters 
in many words, such as the ‘“‘o” in leopard, 
the “b’” in doubt, the “g” in reign, which are 
quite functionless, but tell us something about 
the history of the words. 

(ec) It is a simple but eloquent fact that the 
geological record in the fossil-bearing rocks shows 
the gradual appearance of higher and_ higher 
forms. At a certain stage in the history of the 
earth all the animals were Invertebrates; then 
fishes appeared, then amphibians, then reptiles, 
then birds and mammals. As the ages have 
passed, life has been slowly creeping upwards. 
The rock-record corresponds in its sequences 
with those deducible from comparative anatomy 
and embryology. 

Furthermore, the rock-record reveals quite a 
number of connecting links, such as Archeopteryz, 
the oldest known bird, which has some distinctly 
reptilian features, and a larger number of generalised 
types, such as Phenacodus, one of the ancestors 
of the horse lineage, which bind together several 
subsequently specialised families, or even orders. 

In certain cases, where fossils have been ob- 
tained from successive strata, the paleontological 
series 18 wonderfully complete, and the various 
stages in the evolution of tooth, or limb, or shell 
appear like the stages in individual development. 


WHAT WE OWE TO DARWIN 25 


Thus there is convincing completeness in the 
series uniting various species of the freshwater 
snails, Paludina and Planorbis, and various types 
of Ammonites. In the same way the remarkable 
series of fossil horses, elephants, and crocodiles, 
are either records of pedigree or conundrums. 

(f) The development of the individual is often 
in some measure interpretable as a condensed 
recapitulation of the presumed racial evolution. 
The individual, as Prof. Milnes Marshall said, 
climbs up its own genealogical tree. Ontogeny 
tends to recapitulate phylogeny, especially as 
regards the stages passed through by a particular 
organ, such as the brain or the heart. In their 
early stages there 1s a remarkable resemblance 
between the embryos of the higher Vertebrates : 
they seem, as it were, to travel for some distance 
along the same road before they diverge on their 
several paths. Giull-slits occur in the development 
of the embryos of reptiles, birds, and mammals, 
although they have no respiratory significance and 
are not of any use at all except that one seems to 
become the Eustachian tube connecting the ear 
with the back of the mouth. The young tadpole 
of the frog is fish-like in many details, eg. as 
regards the heart and circulation. The very 
unsymmetrical flat fishes, such as flounder and 
sole, pass through a symmetrical stage. In Fritz 
Miiller’s “ Facts for Darwin” the recapitulation 
idea was applied in detail to Crustaceans, and it 
seems impossible to understand the often very 
circuitous development unless it has an historical 
significance. 

(g) The facts of geographical distribution in 
past and present suggest the gradual dispersal of 


26 DARWINISM AND HUMAN LIFE 


races from centres where they had their original 
headquarters. Peculiar cases, such as the present- 
day distribution of Camelide, or the fauna of 
Australia, or the population of oceanic islands, 
readily admit of evolutionist interpretations. 

We have not given prominence to the so-called 
evidences of evolution, partly because they have 
been stated so often—e.g. by Romanes and by 
Milnes Marshall—partly because none of the so- 
called evidence is in itself demonstrative in the 
strict sense. All that 1s shown is that the formula 
fits a wide and representative series of facts, and 
enables us to think of them in a clear and rapid 
way. What can be securely said is this, that all 
biological facts can be used as evidence of evolution 
if we know enough about them, and there are no 
biological facts which are inconsistent with it, 
so far as we know. 

CoMPARISON OF EvoLuTION FoRMULA AND 
GRAVITATION Formuta.—Let us compare the 
evolution theory with one of the great physical 
generalisations—the gravitation formula. Both 
are simple in statement, both are wide as the 
world in their applicability. We are aware of 
no facts contradictory to either. Furthermore, 
they are alike in this, that neither proposes any 
ultimate explanation, that both are examples 
of intellectual shorthand, of thought-economising, 
descriptive formule. We do not know why 
one body attracts another in the manner which 
Newton formulated; we do not know why 
life should have its power of slowly creeping’ 
upwards. It has been pointed out that, just as 
Newton started with gravitation as a big funda- 
mental fact, so Darwin started from variation, 


WHAT WE OWE TO DARWIN 27 


and that both left their fundamental assumption 
from experience unexplained. 

But there is this difference between the gravi- 
tation formula and the evolution idea, that the 
experimental vindication of the first 1s easy, 
while that of the second is, to say the least, ex- 
tremely difficult. Whether we study the apples 
falling in the orchard or the planets in their courses, 
we can continually confirm the accuracy of the 
gravitation formula, to which two centuries have 
not added anything essential, from which two 
centuries have taken nothing away. 

But the evolution doctrine does not rest on a 
foundation of this sort. Like wisdom, it is justified 
of its children—by half a century’s using—and 
to speak of proving it is to misunderstand it. 

Before passing from the general idea of organic, 
evolution we must point out that it is no mere 
doctrine of the schools, but an important human 
asset—of practical and emotional, as well as of 
intellectual value. In accepting the evolution 
idea we lose no small part of its virtue if we do 
not visualise it, if we do not, in some measure, 
image the relative simplicity of life’s beginnings 
and the long pageant that has passed in gorgeous 
procession over the earth for millions of years ; 
if we do not understand that evolution is going 
on still and that it includes us and our doings in 
its sweep. 


1 Emile Ferriére illustrates the theory of organic evolution 
very clearly by drawing a parallel between species and languages. 

A language may have many varieties, just as a species often 
has. In both cases there is evidence of slow transformation and 
of demonstrable pedigrees. Changes may be observed in actual 
occurrence alike in languages and in organisms. It is possible 
in both to distinguish changes arising fronr within (intrinsio varia- 


28 DARWINISM AND HUMAN LIFE 


(VI) THe Descent AND Ascent oF Man.— 
What do we owe to Darwin? A recognition of 
man’s solidarity with the rest of creation, of his 
affiliation to a Simian stock. In the cumulative 
argument of the “Descent of Man,” Darwin 
disclosed the rock whence he was hewn and the 
pit whence he was digged, showing, not exactly 
that “man sprang from a monkey,” as the vulgar 
idea is, but that man and anthropoid apes are 
collateral branches from a common Primate stock 
which remains hidden in obscurity. 

Darwin gave details of the all-pervading simi- 
litude of structure between man and the anthropoid 
apes, to which the researches of recent years 
have added such striking items as a sameness 
in blood-reaction to Friedenthal’s test. He showed 
how we carry about with us a museum of relics 
indicative of our ancestry—a museum whose 
catalogue now amounts, according to Wiedersheim, 
to about a hundred items. The anatomical re- 
semblances between adult man and adult apes 
are associated with even closer resemblances in 
the embryos, and gain additional significance 
when we take into account the scanty skeletal 
remains of primitive man, the lower races of 
men, and the occurrence of almost sub-human 
types occasionally born in times of distress. 
The affiliation applies to mind as well as 
body, for there is an ever-growing mass of 


tions) from changes imposed from without (extrinsic modifications), 
Young stages of a language show embryonic features, just as 
languages that have been evolving for centuries show vestigial 
structures, such as the familiar unsounded letters in words. There 
are fossil languages, just as there are fossil species. Both in 
languages and in species we can recognise the operation of selective 
processes and the effect of isolation. 


WHAT WE OWE TO DARWIN 29 


facts relating to peculiar psychoses in child and 
adult which we must recognise as vestigial and 
recapitulatory.? 

Those who feel a repugnance to the Darwinian 
conclusion that man is descended from a humble 
Simian ancestry should remember the marvellous 
ascent in each individual lifetime. Neither the 
dignity nor the value of a result is affected by 
the historical conditions of its becoming. And 
if man is separated off by reason (or the power of 
conceptual inference), by morality (or the habit 
of controlling his conduct in reference to ideals), 
by the possession of true language or Logos, and 
by other qualities distinctively human, then we 
must increase our respect for, and see more in, 
that brute creation which contained the potenti- 
ality of all. For it is a fundamental idea of 
evolution that there is nothing in the end which 
is not also in the beginning. 

(VII) Liperation oF INTELLIGENCE.—What do 
we owe to Darwin? A great liberation of the in- 
telligence. Like Abraham Lincoln, who was born 
on the same day in the same year, Darwin worked 
for freedom, though perhaps without ever thinking 
of it. As Prof. H. EH. Crampton has said: 
“The ‘ Origin of Species’ has proved a veritable 
Magna Charta of intellectual liberties, for, as 
no other single document before or since, it has 
released the thoughts of men from the trammels 
of unreasoned conservatism and dogmatism.” 
Speaking of his first impressions of the ‘ Origin 


1 Prof. Stanley Hall gives, as an illustration, “the new psychology 
of crime and criminals, who are so shot through, body and soul, 
with atavisms that only the early history of the race can explain 
them.” 


30 DARWINISM AND HUMAN LIFE 


of Species,” Sir Francis Galton has told us that 
his dominant feeling was one of freedom. 

For one must remember that Darwin attacked 
a whole series of problems which, for most of 
his contemporaries, were either insoluble mysteries 
or a preserve for transcendental interpretation. 
“ Evolution,” Prof. Bateson says, “is a process 
of variation and heredity. The older writers, 
though they had.some vague idea that it must 
be so, did not study variation and _ heredity. 
Darwin did, and so begat, not a theory, but a 
science.” ! He showed that the deeper mysteries 
of life were in a measure accessible to the scientific 
method. He won freedom for the application of 
the evolution formula to man as well as to other 
creatures, and not only to his body, but to his 
emotions and behaviour. He was one of the 
founders of genetic psychology, which, though 
still hardly above the ground, is destined to 
make for the growing freedom of the human 
spirit. We mean not merely intellectual freedom 
from obscurity, but a practical freedom as well; 
for in regard to the mind, as well as the body, 
Darwin set a-going a kind of inquiry into individual 
development and racial evolution, into variation 
and heredity, which promises to give us a firmer 
control of life. We are only beginning to realise 
that the truth which is in Darwinism shares with 
all truth the power of making us free. 

Darwin gave men confidence in the interpre- 
tative value of the evolution formula, which 
makes the present less obscure by throwing on 
it the light of the past, and every one knows how 
the interpretation has been applied to mind, 

1 “ Darwin and Modern Science,” (1909), p. 88. 


WHAT WE OWE TO DARWIN 31 


to morals, to language, to art, to customs, to 
religion. Even the evolution theory has had 
its evolution, and is still, happily, being evolved. 

Of the wide diffusion of the evolutionary way 
of looking at things which Darwin justified, we 
give a single example, as a diagram as it were. 
Aiter the disaster of Kd6nigeriitz the Austrian 
Parliament met to consider what steps should 
be taken for the re-consolidation of the monarchy, 
and a distinguished member of the Upper House 
began a famous speech with the words, “ The first 
thing we have to consider is: Is Charles Darwin 
right, or 1s he not ? *’—*‘ and upon the rightness of 
Darwin’s theory it was gravely proposed to re- 
construct the Austrian monarchy.” ! 

Darwin once expressed satisfaction that he 
had not been permitted to become a “ specialist ”’ ; 
it is hardly too much to say that there is no 
specialism in natural science which he has left 
unaffected by his influence. 

(VII) Ipeat oF Sotentiric Moop anp Mretuop. 
—What do we owe to Darwin? An ideal of 
the scientific mood and of scientific workmanship. 
As it will be a long time before Science weeps, like 
Alexander, having no more worlds to conquer, 
perhaps this ideal is not the least of Darwin’s 
legacies. If we can follow Darwin in the spirit, 
not necessarily in the letter, we shall not go far 
astray. As Prof. T. H. Morgan finely says: 
“Tt is the spirit of Darwinism, not its formule, 
that we proclaim as our best heritage.” For 
this reason, and because the scientific spirit is a 
big fact in modern life, let us consider the features 


1 See Sir Archibald Geikie’s Speech at the Darwin-Wallace 
Celebration, Linnean Society (July Ist, 1908), p. 53. 


32 DARWINISM AND HUMAN LIFE 


of the scientific mood, and Darwin’s illustration 
of them. 

In his stimulating presidential address at the 
meeting of the British Association at Dover in 
1899, Sir Michael Foster discussed the distinctive 
features of the scientific spirit—of which he was 
himself a fine embodiment. His answer was that 
the features of the fruitful scientific mood are 
in the main three—truthfulness, alertness, and 
courage. (1) “The seeker after truth must him- 
self be truthful—truthful with the truthfulness of 
nature.” (2) “He must be alert of mind, ever 
on the watch, ready at once to lay hold of Nature’s 
hint, however small; to listen to her whisper, 
however low.” (3) “ Scientific inquiry has need of 
the moral quality of courage—not so much the 
courage which helps a man to face a sudden 
difficulty, as the courage of steadfast endurance.” 
To the objection that truthfulness, alertness, and 
courage are virtues belonging to almost every one 
who has commanded or deserved success, Sir 
Michael answered: “ That is exactly what I 
would desire to insist, that men of science have 
no peculiar virtues, no special powers. They are 
ordinary men, their characters are common, even 
commonplace. Science, as Huxley said, is organ- 
ised common sense, and men of science are common 
men, drilled in the ways of common sense.” 

CHARACTERISTICS OF SCIENTIFIC Moop : Passion 
AND REVERENCE FoR Facts.—But let us consider 
the scientific mood more analytically. The first 
characteristic of the scientific mood is a passion 
and reverence for facts. , Long ago Bacon said: 
“We should accustom ourselves to things them- 
selves’; and to distinguish between appearance 


WHAT WE OWE TO DARWIN 33 


and reality is part of the unending business of 
science. Faraday said that the scientific investi- 
gator should be “not a respecter of persons, but 
of things.” It was Huxley who spoke of “ that 
enthusiasm for truth, that fanaticism of veracity, 
which is a greater possession than much learning ; 
a nobler gift than the power of increasing know- 
ledge.” Darwin was a fine illustration of this 
passion for facts; there have been few naturalists 
more careful as to data. He began collecting facts 
in regard to the work of earthworms when a 
young student in Edinburgh, and he published 
his fascinating book the year in which he died. 
His gardener said: “‘ He moons about in the 
garden, and I have seen him stand doing nothing 
before a flower ten minutes at a time.” 
Scientiric Caurion.—Ilollowing from the pas- 
sion of facts 1s a second characteristic of the 
scientific mood, namely, cautiousness, or distrust 
of finality and dogmatism of statement. Prof. 
W. K. Brooks says, in his “ Foundations of 
Zoology’: “The hardest of intellectual virtues 
is philosophic doubt, and the mental vice to 
which we are most prone is our tendency to believe 
that lack of evidence for an opinion is a reason 
for believing something else. . . . Suspended judg- 
ment is the greatest triumph of intellectual dis- 
cipline.” As Huxley said: “ The assertion that 
outstrips the evidence is not only a blunder but 
a crime.” As Karl Pearson says: “ The scientific 
man has, above all things, to strive at self-elimina- 
tion in his judgments, to provide an argument which 
is as true for each individual mind as for his 
own.” What a fine temper there is in Darwin’s 
statement—‘I have steadily endeavoured to 


3 


34 DARWINISM AND HUMAN LIFE 


keep my mind free so as to give up any hypothesis, 
however much beloved—and I cannot resist 
forming one on every subject—as soon as facts are 
shown to be opposed to it.” “I had,” he says, 
“during many years followed a golden rule, namely, 
that whenever a published fact, a new observation 
or thought came across me, which was opposed 
to my general results, to make a memorandum 
of it without fail, and at once; for I had found, 
by experience, that such faets and thoughts were far 
more apt to escapefrom the memory than favourable 
ones.” Let us remember how Darwin opened his first 
note-book in 1837, conceived the idea of natural 
selection in 1838, sent a sketch of the theory to 
Hooker in 1844, read his joint-paper with Wallace 
in 1858, and published “‘ The Origin of Species ”’ in 
1859. These dates are eloquent. It is interesting 
to notice that Wallace wrote his sketch in a week 
—the thought-stream of his fevered brain in spate. 

CLEARNESS OF Viston.—A third characteristic 
of the scientific mood is dislike of obscurities, of 
blurred vision, of fogginess. Ignorance in itself 
is no particular reproach, if it is not carried too 
far, but it 1s essential to know when we know 
and when we do not. The mole has a strange 
half-finished lens, which is physically incapable 
of throwing a precise image on the retina. If 
there is any image, it must be a blurred tangle 
of lines. In our busy lives we tend to acquire 
mole-like lenses in regard to particular orders of 
facts; we see certain things clearly, others are 
blurs; but the scientific mood is in continual 
protest against obscurities, insisting upon lucidity. 
One of Bacon’s most historically true aphorisms 
declares “ Truth to emerge sooner from error 


WHAT WE OWE TO DARWIN 35 


than from confusion.” Now we may claim for 
Darwin the quality of definiteness and lucidity. 
He was convinced of the efficacy of natural 
selection, and his exposition, though rarely elegant, 
is always clear. He did not understand how 
variations in the direction of fitness arose, and 
he said so. His yea was yea, and his nay, nay. 

SENSE OF INTERRELATIONS.—A fourth charac- 
teristic of the scientific mood is a sense of the 
interrelations of things. The realisation of Nature 
as a great interconnected system 1s, indeed, one 
of the ends of science; to be on the outlook for 
interrelations 1s diagnostic of the scientific mood. 
We have seen how Darwin had the vision of the 
web of life with pre-eminent vividness. 

Darwin’s Metnop or Workine.—As to Dar- 
win’s method of working, he tells us himself three 
things: (1) that he had from his earlest youth 
a desire to explain things, and that he could not 
resist forming an hypothesis on every subject; 
(2) that he accumulated large collections of facts 
and tried to formulate them in a general law; 
and (3) that he sought to anticipate all possible 
objections to his conclusion. In short, he was a 
deductive-inductive philosopher. 

In speaking of Darwin’s services, Romanes 
said: “A true scientific judgment consists in 
giving a free rein to speculation on the one hand, 
while holding ready the brake of verification with 
the other. Now it is just because Darwin did 
both these things with so admirable a judgment 
that he gave to the world of natural history so 
good a lesson as to the most eflective way of 
driving the chariot of science.” ? 


1 “Darwin and After Darwin” (1897), vol. i. p. 7. 


36 DARWINISM AND HUMAN LIFE 


Prof. Karl Pearson says, in his “ Grammar of 
Science,” that the scientific method is marked by 
the following features: “ (a) careful and accurate 
classification of facts and observation of their 
correlation and sequence; (0) the discovery of 
scientific laws by aid of the creative imagination ; 
and (c) self-criticism and: the final touchstone of 
equal validity for all normally constituted minds.” 
The writer had Darwin as well as Newton in 
mind when he framed this useful definition. 

DARWIN ON HIS OWN SuCccESS.—-No one who has 
read Darwin’s “ Autobiography ” can forget how 
he himself deals with the question of his success. 
““My success as a man of science, whatever this 
may have amounted to, has been determined, as 
far as I can judge, by complex and diversified 
mental qualities and conditions. Of these, the 
most important have been—the love of science, 
unbounded patience in long reflecting over any 
subject, industry in observing and collecting facts, 
and a fair share of invention as well as of common 
sense. With such moderate abilities as I possess, 
it is truly surprising that I should have influenced 
to a considerable extent the belief of scientific 
men on some important points.”’ 

Darwin’s ACHIEVEMENTS.—Let us turn from 
that humility of greatness once more to the actual 
achievement. The idea of organic evolution, older 
than Aristotle, slowly developed from the stage 
of suggestion to the stage of verification, and 
the first convincing verification was Darwin’s ; 
from being an a priore anticipation it has become 
a detailed interpretation of nature, and Darwin 
is still the chief interpreter ; from being a modal 
interpretation of the manner in which living 


PLATE II 














DIAGRAMMATIC GENEALOGICAL TREE OF ANIMALS. 


Mes. Mesozoa: very simple multicellular animals; Onye. Onychophora: e.g. 
Peripatus; Myr. Myriopods: centipedes and millipedes; Lim. Limulus: king-crab ; 
Bra. Brachiopods: lamp-shells; Bry. Bryozoa or Polyzoa: e.g. sea-mat; B. 
Balanoglossus: Enteropneusts; Lan. Lancelet: Amphioxus; Tun. ‘Tunicates or 
Ascidians ; Hypo. Hypostomes: extinct jawless vertebrates; Cyclo. Cyclostomes : 
e.g. lamprey and hag; D. Dipnoi or Mud-fishes; El. Elasmobranchs or Gristly Fishes ; 
Tel. Teleosts or Bony Fishes; Oph. Ophidia: snakes; Lac. Lacertilia: lizards ; Sph. 
Sphenodon or Hatteria : New Zealand“ lizard’ ; Croc. Crocodilians ; Chel. Chelonians. 


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WHAT WE OWE TO DARWIN 37 


creatures have come to be, it has advanced to the 
rank of a causal theory, the most convincing part 
of which men will never cease to call Darwinism. 

In referring to Darwin’s services, Huxley wrote : 
“Whatever be the ultimate verdict of posterity 
upon this or that opinion which Mr. Darwin pro- 
pounded ; whatever adumbrations or anticipations 
of his doctrines may be found in the writings of 
his predecessors; the broad fact remains that, 
since the publication, and by reason of the publica- 
tion, of “ The Origin of Species’ the fundamental 
conceptions and the aims of students of living 
nature have been completely changed. . . . But 
the impulse thus given to scientific thought rapidly 
spread beyond the ordinarily recognised limits 
of biology. Psychology, ethics, cosmology were 
stirred to their foundations, and ‘The Origin of 
Species ’ proved itself the fixed point which the 
general doctrine needed in order to move the 
world.” 

Co-OPERATING InFLUENCES.—To understand how 
all this came about we must get beyond the person- 
ality of Darwin. We must shake ourselves free 
from all creationist appreciations of Darwin and 
Darwinism; we must recognise the services of 
pioneers who helped to make the time ripe— 
notably, for instance, Robert Chambers, whose 
work has seldom been adequately appreciated ; 
we must inquire into the acceptance of evolutionary 
conceptions in regard to other than biological 
orders of facts; we must realise how the growing 
success of scientific interpretation along other 
lines gave confidence to those who refused to 
admit that there was any domain from which 
science could be excluded as a trespasser; we 


— 6-38 DARWINISM AND HUMAN LIFE 


must take account of the development of philo- 
sophical thought—for instance in Herder, Kant, 
and Hegel; we should also, if we are wise enough, 
consider social changes. In short, we must abandon 
the idea that we can understand a great step 
like the acceptance of the evolutionist outlook 
without getting beyond the individual prophet, 
without associating his work with contemporary 
evolution in other departments of activity. The 
man and the moment must agree, and, as Professor 
R. M. Wenley says in this very connection, “* genius 
rarely achieves supremacy without the co-operant 
“social mind.’ ”’ 

There is a risk of attaching too much importance 
to the force of individual effort on the one hand, 
and to the ripening of public opinion on the other. 
The storm of opposition roused by the publication 
of “The Origin of Species ” shows how far the 
time was from being ripe. To say, as Samuel 
Butler said, “‘ Buffon planted, Erasmus Darwin and 
Lamarck watered, but 1t was Mr. Darwin who 
said ‘That fruit is ripe’ and shook it into his 
lap,” seems to us as wilful a perversion of historical 
fact as that other statement by the same ingenious 
and often well-advised critic, ““ Darwin was heir to 
a discredited truth, and left behind him an ac- 
credited fallacy.”” Much more accurate is Huxley’s 
fine pronouncement’: ‘‘ None have fought better, 
and none have been more fortunate, than Charles 
Darwin. He found a great truth trodden underfoot, 
reviled by bigots, and ridiculed by all the world; he 
lived long enough to see it, chiefly by his own efforts, 
irrefragably established in science.” That the time 
was far from ripe is shown by Darwin’s foreboding : 


1 <* Darwiniana,”’ p. 247 


WHAT WE OWE TO DARWIN 39 


“When my notes are published I shall fall infinitely 
low in the opinion of all sound naturalists; so this 
is my prospect for the future.” That the. time 
was far from ripe is well shown in a passage in the 
second volume of Buckle’s “ History of Civilisa- 
tion,’ which was published two years after “ The 
Origin of Species”: “ We are in that predicament 
that our facts have outstripped our knowledge, 
and are now encumbering its march. The publica- 
tions of our scientific institutions, and of our 
scientific authors, overflow with minute and 
countless details, which perplex the judgment, 
and which no memory can retain. In vain do 
we demand that they should be generalised and 
reduced into order. Instead of that, the heap 
continues to swell. We want ideas, and we get 
more facts. We hear constantly of what nature 
is doing, but we rarely hear of what man is thinking. 
Owing to the indefatigable industry of this and 
the preceding century, we are in possession of a 
huge and incoherent mass of observations, which 
have been stored up with great care, but which, 
until they are connected by some presiding idea, 
will be utterly useless.” And yet one of the 
greatest of generalisations, one of the most powerful 
of presiding ideas, was awaiting Buckle’s recogni- 
tion. It was eminently characteristic of Darwin 
that the accumulation of facts was to him not 
an end but a means to an end. 

PaRTICULAR Reasons FoR DARWIN'S SUCCESS.— 
We must grant that the intellectual temper of 
the time was changing, that in various departments 
men were becoming familiar with the historical 
method—the first step to becoming evolutionists, 
that the genetic view of nature was insinuating 


40 DARWINISM AND HUMAN LIFE 


itself like a slow incoming tide in men’s minds, 
and that the scientific spirit had ripened since 
the days when Cuvier laughed Lamarck out of 
court, but we must still ask, more personally, how 
it was that Darwin succeeded so well. There are 
several answers. 

Because, in the first place, he had clear visions— 
pensées de la jeunesse, exécutees par Vage mur— 
which a University curriculum had not made 
impossible, which the Beagle voyage—a Columbus 
voyage that discovered-a new world—had made 
vivid, which an unrivalled British doggedness 
made real—visions of the web of life, of the fountain 
of change within the organism, of the struggle for 
existence, of discriminate winnowing or selection, 
and of the spreading genealogical tree. 

Because, in the second place, he put so much 
grit into the verification of his visions, forcing 
them to the proof in an argument which is, of 
its kind—direct demonstration being out of the 
question—quite unequalled. 

Because, in the third place, he broke down 
the opposition which the most scientific had felt 
to the seductive modal formula of evolution, by 
bringing forward a more plausible theory of the 
process than had been previously suggested. Nor 
can one forget, since questions of this magnitude 
are human and not merely academic, that Darwin 
wrote, of his condescension, so that all men could 
understand. 

As Mr. Arthur Balfour recently said: ‘‘ Charles 
Darwin’s performances have now become part 
of the common intellectual inheritance of every 
man of education, wherever he lives or whatever 
his occupation or trade in life. To him we trace, 


WHAT WE OWE TO DARWIN 41 


in the main, the view which has affected, not 
merely our ideas of the development of living 
organisms, but our ideas upon politics, upon 
sociology, ideas which cover the whole domain of 
human terrestrial activity. He is the fount and 
origin, and he will stand for all time as the man 
who has made this great, and, as I think, beneficent 
revolution in the mode in which educated men 
can see the history, not merely of their own institu- 
tions, not merely of their own race, but of 
everything which has that unexplained attribute 
of life, everything that lives on the surface of 
the globe or within the depths of the ocean.”’! 

In any case, we must agree with what Huxley 
says of Darwin: “It is only by pursuing his 
method, by that wonderful single-mindedness, 
devotion to truth, readiness to sacrifice all things 
for the advance of definite knowledge, that 
we can hope to come any nearer than we are 
at present to the truths which he struggled to 
attain.”’ 

Darwin was no metaphysician; he always kept 
very close to earth—which is half the secret of 
the persistent strength of his teaching. For this 
reason, most appropriately, Prof. R. M. Wenley 
ended a very suggestive address? on Darwin by 
quoting, in reference to Darwin’s services, the 
fine words of a Scottish poet: 


Man’s thought is like Antzus, and must be 
Touched to the ground of Nature to regain 
Fresh force, new impulse, else it would remain 
Dead in the grip of strong Authority. 


1 Nature, July Ist, 1909. 
® Popular Science Monthly (1909), vol. Ixxiv. p. 395, 


42 DARWINISM AND HUMAN LIFE 


But, once thereon reset, tis like a tree, 
Sap-swollen in spring-time: bonds may not restrain 3 
Nor weight repress; its rootlets rend in twain 
Dead stones and walls and rocks resistlessly. 
Thine, then, it was to touch dead thoughts to earth, 
Till of old dreams sprang new philosophies, 
From visions systems, and beneath thy spell 
Swiftly uprose, like magic palaces,— 
Thyself half-conscious only of thy worth— 
Calm priest of a tremendous oracle ! 


CHAPTER II 
THE WEB OF LIFE 


43 





CHAPTER II 


THE WEB OF LIFE 


Correlation of Organisms as well as Correlation of Organs—What 
the Metaphor of ‘‘ The Web of Life’’ suggests—Dependence of 
Living Creatures upon their Surroundings—Nutritive Chains 
—Nexus between Mud and Clear Thinking—Correlation 
between Catches of Mackerel and Amount of Spring Sunshine 
—Nutritive Chains in the Deep Sea—Dependence of one 
Organism on another for the Continuance of the Species 
—Darwin’s Instance of the Connection between Cats and 
Clover—Scattering of Seeds—Interrelations between Fresh- 
water Mussels and Fishes—Life-histories of Parasites—Far- 
reaching Influence of Certain Animals: Earthworms—Termites, 
or White Ants—The Hand of Life upon the Earth—Practical 
Importance of a Realisation of the Web of Life. 


NATURALISTS, in the true sense, who study the 
life of living creatures in nature, have always 
been distinguished by a keen perception of the 
inter-relations of things. Whether we take Gilbert 
White as representing the old school, or W. H. 
Hudson as representing the new, we get from 
their observations the same impression of nature 
as a vibrating system, most surely and subtly in- 
ter-connected. But it seems just to say that no 
naturalist, before or since, has come near Darwin 
in his realisation of the web of life, in his clear 
vision and picture of the vast system of linkages 
that penetrates throughout the animate world. 
CoRRELATION OF ORGANISMS AS WELL AS CORRE- 
LATION OF Oraans.—In thinking of a living body 


we are accustomed to the idea of the correlation of 
45 


46 DARWINISM AND HUMAN LIFE 


organs. Itis of the very nature of an organism that 
there should be mutual dependence among its parts. 
The organs are all partners in the business of life, 
and if one member changes others also are affected. 
This 1s especially true of certain organs that have 
developed and evolved together, and are knit by 
close physiological bonds. We know in health 
how nerve and muscle, brain and sense-organs, 
heart and lungs, are closely bound together in the 
bundle of life. We know in disease that a change 
in one organ often affects another, and the fact 
remains, though the nexus is sometimes mysterious. 
The state of our liver may give colour to our whole 
intellectual firmament, and a slight ocular de- 
rangement may warp a wise man’s philosophy. 
The far-reaching importance of a little organ like 
the thyroid gland beside the larynx 1s well known ; 
our intellectual as well as our bodily health de- 
pends on its soundness. Now, just as there is 
a correlation of organs within the body, so there 
is a correlation of organisms in that system of 
things which we call Nature. In both cases we 
are here using the word “correlation ’’ in its deeper 
sense—that the various parts are more than 
mutually dependent, that they are in some measure 
co-ordinated, making larger systems workable. 
Wuat THE Metapuor oF “THe WEB oF LIFE” 
SUGGESTS.—We may use the metaphor “web of 
life’? in two ways. On the one hand, Nature hasa 
woven pattern which science seeks to read, each 
science following the threads of a particular colour. 
There is a warp and woof in this web, which to the 
zoologist usually appear as “ hunger ”’ and “ love.” 
There is a changing pattern in the web, becoming 
more complex as the ages pass; and this is evo- 


THE WEB OF LIFE 47 


lution. But the essential idea of a web is that of 
interlinking and ramifying. We can never tell 
where a thread will lead to. If one be pulled out, 
many are loosened. This is true of Nature through 
and through. 

The phrase “web of life” suggests another 
picture—the web of a spider—often an intricate 
system, with part delicately bound to part, so that 
the whole system is made one. “ The quivering 
fly entangled in a corner betrays itself throughout 
the web; often it is felt rather than seen by the 
lurking spinner. So in the substantial fabric of 
the world part is bound to part. In wind and 
weather, or in the business of our life, we are 
daily made aware of results whose first conditions 
are very remote; and chains of influence, not 
dificult to demonstrate, link man to beast, and 
flower to insect. The more we know of our 
surroundings the more we realise that nature is 
a vast system of linkages, that isolation is im- 
possible.” * 

DEPENDENCE OF LIVING CREATURES ON THEIR 
SuRROUNDINGS.—We do not know what life in 
principle is, but we may describe living as action 
and reaction between organisms and their en- 
vironment. This is the fundamental relation— 
the dependence of living creatures on appropriate 
surroundings, and the primary illustrations of 
linkages must be found here. The living creatures 
are real, just in the same sense as the surroundings 
are real; but it is plain that we cannot abstract 
the living creatures from their surroundings. 
When we try to do this they die—-even in our 
thought of them, and our biology is only necrology. 


1 “The Study of Animal Life,” by J. Arthur Thomson (1890). 


& 


48 DARWINISM AND HUMAN LIFE 


Huxley compared a living creature to a whirlpool 
in a river; it is always changing, yet always 
apparently the same; matter and energy stream 
in and stream out; the whirlpool has an individu- 
ality and a certain unity, yet it 1s wholly dependent 
upon the surrounding currents. One may push 
the whirlpool metaphor too far, so as to give a 
false simplicity to the facts, for when vital whirl- 
pools began to be there also emerged what cannot 
be discerned in crystal or dewdrop—the will 
to live, a capacity of persistent experience, and 
the power of giving rise to other lives. To ignore 
this is to attempt a falsely simple natural history. 
But what Huxley’s metaphor of the whirlpool 
does vividly express is the dependence of living 
creatures on their surroundings. We cannot under- 
stand either the whirlpool or the trout apart from 
the stream. 

When we think out this fundamental dependence 
upon surroundings, we see, for instance, that all 
our supplies of energy, all our powers of every 
kind—with our own hands, or by the use of animals, 
or by means of machinery—are traceable to the 
sun. Or again, it is easy to show that our society 
depends fundamentally not on gold, but on iron. 
We depend for food on plants and animals, and 
through these animals on plants ultimately ; 
the plants feed upon air, water, and salts, which, 
with the aid of the energy of the sunlight, they 
build up into complex organic compounds; they 
cannot do this unless the sun shines through a 
screen of green pigment called chlorophyll; there 
cannot be chlorophyll without iron; therefore our 
whole social framework is founded on IRon. 

Nutritive Cuaains.—Plants feed on their in- 


THE WEB OF LIFE 49 


animate environment in a direct way that is 
impossible to animals, so we pass insensibly from 
dependence on surroundings to those nutritive 
chains which bind living creatures together in 
long series often quaintly suggestive of ‘ The 
House that Jack Built’ and similar old rhymes. 
We have ceased to wonder at the circulation of 
the blood in our body; have we begun to wonder 
enough at the ceaseless circulation of matter in 
the system of nature? As Heraclitus said, zavra 
pet, all things are in flux. “ The rain falls; the 
springs are fed; the streams are filled and flow 
to the sea; the mist rises from the deep and the 
clouds are formed, which break again on the 
mountain-side. The plant captures air, water, 
and salts, and, with the sun’s aid, builds them up 
by vital alchemy into the bread of life, incorporating 
this into itself. The animal eats the plant, and a 
new incarnation begins. All flesh is grass. The 
animal becomes part of another animal, and the 
reincarnation continues.”! The silver cord of the 
bundle of life is loosed, and earth returns to earth. 
The microbes of decay break down the dead, and 
there is a return to air and water and salts. We 
may be sure that nothing real is ever lost; we are 
sure that all things flow. Penelope-like, Nature 
is continually unravelling her web and making a 
fresh start. 

NEXUS BETWEEN Mup AND CLEAR THINKING.— 
To keep a famous inland fish-pond from giving 
out, some boxes of mud and manure were placed 
at the sides. Bacterla—the minions of all putre- 
faction—worked in the mud and manure, making 

1 “The Bible of Nature,” by J. Arthur Thomson (1908). 
(Scribner, New York. Clark, Edinburgh.) 

4 


50 DARWINISM AND HUMAN LIFE 


food for minute Infusorians, which multiply so 
rapidly that there may be a million from one in 
a week’s time. A cataract of Infusorians over- 
flowed from box to pond, and the water-fleas and 
other small fry gathered at the foot of the fall 
and multiplied exceedingly. Thus the fishes were 
fed, and, as fish-flesh is said to be good for the 
brain, we can trace a nexus from mud to clear 
thinking. What was in the mud became part of 
the Infusorian, which became part of the Crus- 
tacean, which became part of the fish, which 
became part of the man. And it is thus that 
the world goes round. 

CORRELATION BETWEEN CATCHES OF MACKEREL 
AND AMOUNT OF SPRING SUNLIGHT.—-A curious and 
most interesting correlation has been discovered 
by Dr. H. J. Allen between catches of mackerel 
and the amount of sunlight... The more sunshine 
in May, the more mackerel at Billingsgate. How 
does this work out? Mr. G. E. Bullen? shows 
that “for the years 1903-1907 there appears to 
be a correlation between the number of mackerel 
taken during May and the amount of Copepod 
plankton, upon which the mackerel feed, taken 
in the neighbourhood of the mackerel fishing 
grounds during the same month.” Mr. W. J. 
Dakin ° shows that the food of Copepods consists 
largely of the vegetable organisms of the plankton, 
such as diatoms, and of Infusorian-like organisms 
called Peridinide. But the production of this 
microscopic plankton, the “ stock” of the “‘sea- 
soup, depends partly on the composition of the 


1 Journ. Marine Biol. Assoc. (1909), vol. viii. p. 394. 
3 Ibid. p. 269. 
8 Internat. Revue Hydrobiologie (1908), vol. i. 


PLATE Ill 





NUTRITIVE CHAINS: MACKEREL, COPEPODS, INFUSORIANS, 
AND DIATOMS, 


The plate illustrates diagrammatically the idea of nutritive chains. The mackerel 
feed very largely on Copepods, which are represented devouring the microscopic Peridinid 
Infusorians and the Diatoms of the surface plankton, The gulls and the fisherman 
suggest other complications, 


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ye 





THE WEB OF LIFE 51 


sea-water, partly on the temperature, and partly 
on the amount of light available. There seems to 
be no correlation between the surface temperature 
and the abundance of mackerel, but Dr. Allen has 
shown a correspondence between sunshine and 
the catches. Thus, if all flesh is grass, all fish is 
seaweed, animalcule, and detritus. 

NutTRITIVE CHAINS IN THE DerEp Sea.—lIf we 
pass from the sunlit open sea to the floor of the 
deep sea—that strange, dark, cold, silent, plantless 
world—we find carnivorous animal preying upon 
carnivorous animal through long series—fish feeds 
on fish, fish on crustacean, crustacean on worm, 
worm on still smaller fry, and all ultimately depend 
on the basal food-supply—the ceaseless shower of 
moribund atomies sinking from the surface waters 
many miles, it may be, overhead, like the snow- 
flakes on a quiet winter day. 

DEPENDENCE OF ONE ORGANISM ON ANOTHER 
FOR THE CONTINUANCE OF THE SPECIES.—Passing 
from “nutritive chains,” we may select a few 
illustrations of the dependence of one creature 
upon another for the continuance of its kind. 
The crowning instances are to be found in the 
interrelations between plants and animals which 
secure cross-fertilisation and the distribution of 
seeds. To both of these Darwin devoted much 
attention, and they were always favourite subjects 
with him. 

Every one knows that flowering plants and 
flower-visiting insects have grown up throughout 
long ages together, in alternate influence and 
mutual perfecting. They are now fitted to one 
another as hand to glove. The insects visit the 
flowers for food ; in so doing they carry the fer- 


52 DARWINISM AND HUMAN LIFE 


tilising golden dust from blossom to blossom, so 
that the possible seeds become real seeds. 

In 1793 a Berlin naturalist, Christian Konrad 
Sprengel, like Darwin in his perception of the 
web of life, published a pioneer book entitled 
“The Secret of Nature discovered in the Structure 
and Fertilisation of Flowers,” in which he showed 
that most flowers have nectar which insects 
enjoy; that by the insects’ visits pollination is 
secured ; that there is no detail of the flower without 
its meaning—the colour is a flag to attract the 
insect’s eye, conspicuous spots are honey-guides 
to the explorers, there are arrangements for keeping 
the pollen dry and for dusting it on the insects, 
and so on. If Sprengel had only discovered the 
utility of the cross-fertilisation, which Darwin 
proved experimentally, his work could hardly 
have been overlooked for nearly seventy years. 
In 1841 it came into Darwin’s hands, and im- 
pressed him as being “ full of truth,” although 
“with some little nonsense.” In Darwin’s work 
Sprengel had his long-delayed reward. 

Darwin’s INSTANCE OF THE CONNECTION BE- 
TWEEN CaTs AND Ciover.—One of Darwin’s 
instances of the web of life—given in connection 
with the pollination of flowers—has become 
familiar all over the world. It should never 
become trite to us and it should never be regarded 
as more than a particularly clear illustration of 
a general fact. ‘‘ Plants and animals, remote in 
the scale of nature, are bound together by a web 
of complex relations....I have found, from 
experiments, that humble-bees are almost indis- 
pensable to the fertilisation of the heart’s-ease 
(Viola tricolor), for other bees do not visit this 


PLATE IV 





INTER-RELATIONS: CATS, VOLES, HUMBLE-BEES, PURPLE CLOVER. 


The plate illustrates diagrammatically Darwin’s famous example of inter-relations. 
The purple clover is pollinated by humble-bees; the voles or field-mice destroy the 
bee-grubs in the nests; cats kill voles, The cottage suggests another link, 


52] 





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THE WEB OF LIFE 53 


flower. I have also found that the visits of bees 
are necessary for the fertilisation of some kinds 
of clover—thus, 100 heads of red clover (7r- 
folium pratense) produced 27,000 seeds, but the 
same number of protected heads produced not a 
single seed. Humble-bees alone visit red clover, 
as other bees cannot reach the nectar. . . . Hence 
we may infer as highly probable that, if the whole 
genus of humble-bees became extinct or very 
rare in England, the heart’s-ease and red clover 
would become very rare, or wholly disappear.” 
We know that the red clover imported to New 
Zealand did not bear fertile seeds until humble- 
bees were also imported. ‘“* The number of humble- 
bees in any district depends in a great measure 
on the number of field-mice, which destroy their 
combs and nests; and Colonel Newman, who has 
long attended to the habits of humble-bees, 
believes that more than two-thirds of them are 
thus destroyed all over England.” Now the 
number of mice is largely dependent, as every 
one knows, on the number of cats; and Colonel 
Newman says: “ Near villages and small towns 
I have found the nests of humble-bees more numer- 
ous than elsewhere, which I attribute to the 
number of cats that destroy the mice.” Thus we 
may say, with Darwin, that next year’s crop of 
purple clover is influenced by the number of 
humble-bees in the district, which varies with 
the number of field-mice; that is to say, with the 
abundance of cats! 

SCATTERING OF SEEDS.—It is a fascinating 
chapter of natural history which tells us how 
cross-pollination is eflected—here by a bee and 
there by a butterfly, occasionally by a long-billed 


54 DARWINISM AND HUMAN LIFE 


humming-bird beautifully poised before the flower 
with almost invisibly rapid vibrations of its wings, 
and occasionally by a slowly moving snail of 
epicure appetite. But not less important is the 
part played by animals in the scattering of seeds, 
and here again Darwin gives us the classic case 
of fourscore seeds germinating out of a ball of 
mud from a bird’s foot. From one instance you 
may learn all, and see that much of Darwin’s 
work has been an eloquent commentary on that 
memorable saying about the sparrow that falls 
to the ground. Such a simple event literally 
sends a throb through surrounding nature; we 
can follow its effects a few steps, just as we follow 
for a few yards the ripples made when we throw 
a stone into a still lake: in neither case can we 
doubt that the spreading influences are real, 
though they pass beyond our ken. 
INTERRELATIONS BETWEEN F'RESH-wATER Mus- 
SELS AND Fisues.—As a striking illustration of 
the inter-linking of different forms of life, we 
may take the case of the fresh-water mussels and 
their larve. The fertilised egos develop in the 
outer gill-plate of the mother-mussel, and minute 
bivalve larvee, called Glochidia, are formed. The 
mussel keeps these within the cradle until a fresh- 
water fish—such as the minnow—comes into the 
vicinity, and then she sets them free. In a way 
that we do not understand, the simple constitution 
of the larvee is tuned to respond to the presence of 
minnows and the like, and with snapping valves 
they manage to fix themselves to their host. 
After a short period of temporary parasitism, at 
the end of which there is a metamorphosis, they 
drop off from the fisb into the mud, often far 


THE WEB OF LIFE 55 


from their birth-place. This is curious enough, 
but the idea of linkages becomes incandescent in 
the mind when we note that, just as the fresh-water 
mussel has young temporarily parasitic on fishes, so 
a fresh-water fish, the bitterling (Rhodeus amarus), 
has its young temporarily parasitic in the gills 
of the mussel. 

LIFE-HISTORIES OF ParasiTEs.—When we pass 
to parasites in a stricter sense we find the most 
extraordinary interconnections, the most widely 
separated animals often sharing a parasite between 
them. Liver-rot, which has repeatedly killed a 
million sheep in a year in Britain alone, is due 
to a parasite which passes from sheep to water, 
from water to water-snail, from water-snail to 
grass, from grass to sheep. The tapeworm of the 
cat has its bladder-worm stage in the mouse, the 
sturdie-worm of the sheep’s brain has its tapeworm 
stage in the dog, and similar relations hold for 
hundreds of species. The troublesome thread- 
worm of human blood (fdlarza sanguinis hominis) 
is transferred from man to man by the mosquito, 
and the guinea-worm, which was probably. the 
fiery serpent that vexed the Israelites in the 
desert, which passes into man in drinking-water, 
spends its youth in a minute water-flea, called 
by the giant’s name of Cyclops. The import- 
ance of tse-tse flies in transmitting the minute 
animals which cause sleeping-sickness and allied 
diseases is known to all. We have spoken of the 
connection between cats and clover, and there 
is a not less striking connection between cats 
and plague. For it seems to have been shown 
in India that the more cats the fewer rats, 
and the fewer rats the fewer rat-fleas, which 


56 DARWINISM AND HUMAN LIFE 


are the agents in passing the plague-germs to 
man. 

FAR-REACHING INFLUENCE OF CERTAIN ANIMALS : 
HARTHWORMS.—We realise the idea of the web 
of life in another way when we consider the 
far-reaching influence of particular kinds of acti- 
vity, the best instance being the work of earth- 
worms. In 1777 Gilbert White got at the very 
root of the matter. “The most insignificant 
insects and reptiles are of much more consequence 
and have much more influence in the economy 
of nature than the incurious are aware of.... 
Harthworms, though in appearance a small and 
despicable link in the chain of nature, yet, if 
lost, would make a lamentable chasm... . 
Worms seem to be the great promoters of vege- 
tation, which would proceed but lamely without 
them, by boring, perforating, and loosening the 
soil, and rendering it pervious to rains and the 
fibres of plants; by drawing straws and stalks 
of leaves and twigs into it; and, most of all, 
by throwing up such infinite numbers of lumps 
of earth called worm-casts, which, being their 
excrement, is a fine manure for grain and grass. 
Worms probably provide new soil for hills and 
slopes where the rain washes the earth away; and 
they affect slopes probably to avoid being flooded. 
. .. The earth without worms would soon become 
cold, hard-bound, and void of fermentation, and 
consequently sterile. ... These hints we think 
proper to throw out, in order to set the inquisitive 
and discerning at work. A good monograph of 
worms would afford much entertainment and 
information at the same time, and would open a 
large and new field in natural history.” 


THE WEB OF LIFE 57 


The monograph that Gilbert White wished for 
in 1777 was published by Darwin in 1881, the 
year before he died—“ the completion,” he said, 
“of a short paper read before the Geological 
Society more than forty years ago.” With his 
characteristic thoroughness and patience he worked 
out the part that earthworms have played in the 
history of the earth, and proved that they deserve 
to be called the most useful animals. By their 
burrowing they loosen the earth, making way 
for the plant rootlets and the raimdrops; by 
bruising the soil in their gizzards, they reduce 
the particles to more useful, powdery form; by 
burying the surface with castings brought up from 
beneath, they have been for untold ages ploughers 
before the plough, and by burying leaves they 
have made a great part of the vegetable mould 
over the whole earth. In illustration of the last 
point, we may notice that we recently found thir- 
teen midribs of the leavesof the rowan, or mountain- 
ash, radiating round one hole like the spokes 
of a wheel; the withering leaflets had been carried 
down, and two were sticking up at the mouth of 
the burrow: that meant 91 leaflets to one hole. 
Darwin showed that there often are 50,000 (and 
there may be 500,000) earthworms in an acre; 
that they often pass ten tons of soil per acre 
per annum through their bodies; and that they 
often cover the surface at the rate of three inches 
in fifteen years. Though our British worms only 
pass out about 20 oz. of earth in a year, the weights 
thrown up in a year on two separate square yards 
which Darwin watched were respectively 6°75 Ib. 
and 8°387 lb., which correspond to 14% and 18 
tons per acre per annum. 


58 DARWINISM AND HUMAN LIFE 


We follow the work further and it becomes 
evident that the constant exposure of the soil 
bacteria on the surface is bound to be important, 
on the one hand, in allowing them to be scattered 
by wind and rain, on the other in exposing 
them to the beneficent action of the sunlight— 
which is the most universal, effective, and eco- 
nomical of all germicides. 

In Yorubaland, on the West Coast of Africa, 
Mr. Alvan Mullson calculated that about 62,233 
tons of subsoil are brought every year to the sur- 
face of each square mile, and that every particle 
of earth, to the depth of two feet, is brought to 
the surface once in twenty-seven years. It need 
hardly be added that the district is fertile and 
healthy. 

Earthworms play their part in the disintegration 
of rocks, letting the solvent humus-acids of the 
soil down to the buried surface. Their castings 
on the hill-slopes are carried down by wind and 
rain and go to swell the alluvium of the distant 
valleys or the wasted treasures of the sea. The 
well-known parallel ledges along the slopes of 
grass-clad hills are partly due to earthworm 
castings caught on sheep-tracks, and thus we 
begin to connect the earthworms not only with 
our wheat-supply but with our scenery. Well 
may we say, with Darwin: “It may be doubted 
whether there are many other animals which have 
played so important a part in the history of the 
world as have these lowly organised creatures.” 
Those who wish to understand Darwinism should 
always begin with Darwin’s last book—‘‘ The 
Formation of Vegetable Mould through the Action 
of Worms ” (1881). It illustrates the web of life, 


THE WEB OF LIFE 59 


the idea of which is essential to an understanding 
of the struggle for existence and natural selection. 
But it also illustrates what Darwin had learned 
from Lyell—that great results may be brought 
about by the accumulation of infinitesimal items. 
As Prof. A. Milnes Marshall said: “The lesson 
to be derived from Darwin’s life and work cannot 
be better expressed than as the cumulative import- 
ance of infinitely little things.” 

TERMITES, OR WHITE Ants.—Henry Drummond, 
in his “ Tropical Africa,” tried to make out a case 
for the agricultural importance of termites, or 
white ants. It is well known that these old- 
fashioned insects have a pruning action in the 
forest, destroying dead wood with great rapidity. 
Houses and furniture, fences and boxes, as well 
as forest-trees, fall under their jaws. In some 
places, “if a man lay down to sleep with a wooden 
leg, it would be a heap of sawdust in the morning.” 
But what of the termites’ agricultural importance ? 
The point is that they keep the soil circulating 
by constructing earthen tunnels up the sides of 
trees and posts and by making huge obelisk-like 
ant-hills, or termitaries. ‘“‘ The earth-tubes crumble 
to dust, which is scattered by the wind; the rains 
lash the forests and soils with fury, and wash off 
the loosened grains to swell the alluvium of a 
distant valley.” It must be noted, however, 
that Drummond did not prove his case with sufi- 
cient precision, and there is, as Escherich points 
out in his beautiful study of termites,’ this difficulty, 
that, while the castings of earthworms are soft 
and loose, the earth-tubes and constructions of 
termites are stony. 


i “Die Termiten.” (Leipzig, 1909.) 


60 DARWINISM AND HUMAN LIFE 


Escherich does, however, admit that the termites 
have some agricultural importance, and he points 
out that there are other services to be put to 
the credit side of their account. They prune off 
wood that has begun to go; they destroy rotting 
things, including the bodies of small animals ; 
they make for cleanliness and health. In some 
low-lying tracts, as Silvestri has shown, there are 
dry stretches, “termite islands,” which have 
been gradually built up from the broken-down 
remains of termitaries. -Nor should it be forgotten 
that the white ants are often used as food. On 
the other hand, Escherich does not hesitate to 
rank them as among the great hindrances to 
the spread of civilisation. They insidiously devour 
everything wooden, from the telegraph-post to 
the wooden butt of the gun hanging against the 
wall, from books in the library to corks in the 
cellar. There does not seem sufficiently precise 
information in regard to the living plants that 
they attack, and no safe general statement can be 
made except that their appetite is large and 
catholic. 

With a centre in earthworms, what a variety of 
interests must be included within the radius of 
their life and work!—centipedes, birds, moles, 
seedlings, man. The same is true of termites, 
and two further illustrations may be given. Ob- 
servers have reported about thirty different species 
of termites with the habit of feeding on fungi 
grown within the termitary on specially constructed 
mazy beds. The habit is interesting in many ways ; 
for instance, because the fungi afford a supply of 
nitrogenous material which is scarce in the ordinary 
diet of wood, and also because a similar habit 


THE WEB OF LIFE 61 


occurs in the quite unrelated true ants. Finally, 
the web is illustrated by the numerous boarders, 
mostly beetles, that are found in the termitaries— 
not hostile intruders or parasites, but guests which 
are fed and cared for apparently for the sake of 
a palatable exudation with a pleasant, narcotising 
effect on the termites. With a centre in termites, 
what a variety of interests must we not include 
within the radius of their life and work !—fungi 
and trees, beetles and birds, lizards and ant-eaters, 
and man more than any. | 

THe Hanp or Lire upon THE Hartu.—The 
hand of life has been working upon the earth for 
untold ages. Take plants, for instance. The sea- 
weeds lessen the force of the waves, the lichens 
eat into the rocks, the mosses form huge sponges 
on the moors which keep the streams flowing 
in days of drought. Many little plants are for 
ever smoothing away the wrinkles on the earth’s— 
their mother’s—face, and they adorn her with 
jewels. Others that have formed coal have en- 
riched her with ages of entrapped sunlight. The 
grass—which began to appear in Tertiary ages— 
protects the earth lke a garment; the forests 
affect rainfall and temper climate, besides sheltering 
multitudes of living things, to many of whom every 
blow of the axe is a death-knell. No plant, from 
bacterium to oak-tree, lives or dies to itself, or 
is without its influence upon the earth. So among 
animals there are destructive borers and burrowers 
and conservative agents, such as the coral-polyps 
and the chalk-forming Foraminifera. 

PRACTICAL IMPORTANCE OF A REALISATION OF 
THE WEB OF Lire.—What has Darwinism to do 
with human life? The answer at this stage in 


62 DARWINISM AND HUMAN LIFE 


our inquiry is clear: we must respect the web 
of life if we wish to master Nature. She must 
be humoured, not bullied. Emerson included in 
his vision of a perfected earth the absence of 
spiders, but the absence of spiders—which snare 
so many injurious insects—would mean the absence 
of much else, man probably included. In a 
northern county in Scotland the proprietors were 
justly annoyed at the injuries inflicted on young 
trees by squirrels, and they formed a squirrel- 
club, setting a price on the beautiful rodent’s 
head. Perhaps a wiser course would have been to 
begin by inquiring what disturbance of the balance 
of nature had allowed the squirrels to multiply 
so disastrously. But, after a period of squirrel- 
slaughter and some jubilation thereat, a cloud 
began to rise in the sky. The wood-pigeons were 
multiplying worse than ever, and the farmers, 
at least, said with no uncertain voice that they 
preferred the squirrels. An imperfect recognition 
of the web of life had left out of account the 
notable fact that squirrels destroy large numbers 
of young wood-pigeons. 

One of the hopeful symptoms of the last few 
years is the reawakening of an interest in woods 
and forests. Hvery one knows how terribly these 
have been wasted, and how the disastrous results 
have affected rainfall and irrigation, climate and 
crops, and even the character of the people. Here 
what was once a pleasant stream is now like a 
gravelly road, and there the fertile plains are 
flooded; here the wind is sweeping away the 
soil, and there both beauty and health have 
departed. The birds which the woods once 
sheltered are driven elsewhere, and the insect- 


THE WEB OF LIFE 63 


pests are rife among the crops. For “ the cheapest 
and most effective insecticides are birds.” 

The recognition of consequences—often far- 
reaching—grows with us as we work with the 
idea of the web of life, as we see in proper 
perspective the criminality of those who are 
ruthless. Ex-President Roosevelt’ has declared 
his abhorrence of “‘ the land-skinner ’’—* the in- 
dividual whose idea of developing the country is 
to cut every stick of timber of it, and then leave 
a barren desert for the home-maker who comes 
in after him. That man is a curse, and not a 
blessing, to the country. The prop of the country 
must be the man who intends so to run his business 
that it will be profitable to his children after him.” 
Every right-thinknmg man, and especially those 
who have grasped the idea of the web of life, 
will say with Roosevelt, “ Z am against the land- 
skinner every time.” 

It may be said that man must exterminate a 
good deal if he is to go on peaceably with his 
business, and it will be admitted that there has 
never been a strong enthusiasm, humanitarian or 
otherwise, against the elimination of rattlesnakes, 
and such like. The naturalist’s answer is that 
every crusade should be carefully considered on 
its own merits, and that every careless and hasty 
destruction of life is to be condemned. Even in 
regard to snakes killing may be carried too far. 
Some creatures are, as it were, on the fringes of the 
web, while others occupy a position where many 
threads meet. It is scientifically and esthetically 
deplorable that birds like the great auk and 


1 Quoted by A. H. 8. Lucas in his admirable Presidential Address, 
**Proc. Linnean Soc. N.S.W.” (1908), vol. xxxiii. pp. 1-38. 


64 DARWINISM AND HUMAN LIFE 


mammals like the quagga should have been exter- 
minated, but it is practically much more deplorable 
that we have lost so many hawks and weasels 
and other members of that pertinacious army 
whose guerilla warfare keeps hundreds of more 
humdrum creatures up to the scratch, and keeps 
“vermin ”’ from becoming a plague. Moreover, 
it is extremely difficult to tell what may be the 
consequences of exterminating any creature— 
remote as it may seem from the beaten track of 
human affairs. One of the obvious lessons of 
Darwinism is that we should be slow to call any 
change unimportant. Everything counts, or may 
count. Aso-called unimportant animal is destroyed 
and no immediate ill effects are seen. But who 
can tell ? 

Very pertinent, for instance, is the question : 
What about the parasites that used to complete 
their life-history in romantic routine in this ex- 
tinguished animal? Have we extinguished the 
parasite also? Or is it waiting, with a whip of 
scorpions, to chastise mankind for their ignorance 
of Darwinism ? 

The practical importance of recognising the 
web of life has been proved by the heavy penalties 
which man has often had to pay for disturbing 
the balance of nature, careless of results and 
ruthless of beauty, for not admitting that if we 
would master Nature we must first understand 
her. How much has Australia had to pay for 
the introduction of rabbits in 1860, or America 
for sparrows? Sometimes the introduction has 
been unconscious, and man has only to blame 
himself for letting the intruder take hold, as in 
the case of the Phylloxera in France, or of the 


THE WEB OF LIFE 65 


Colorado Beetle in Ireland. “ Ignorance of nature,”’ 
Mr. A. H. 8. Lucas says, “is costly. By disturbing 
the balance of nature, man has introduced foes 
into his own household.” Speaking of Australia, 
he says: “ How much is needed for the eradication 
of Bathurst Burr, Prickly Pear, Water-hyacinth, 
Bramble and Sweetbriar, Codlin Moth, Waxy 
Scale, Pear Slug, and Red Spider, owing to care- 
lessness or lack of knowledge in early days ? ”? 

An obvious moral is that we should be careful 
in our introductions of new organisms—man 
included—into new surroundings. The primary 
consequences may be predictable, but the secondary 
and the tertiary consequences—who is sufficient 
for these things? We have records of the un- 
conscious introduction of rats into Jamaica, where 
they became a pest. To destroy them mongooses 
were imported, and the rats were soon checked. 
But the mongooses, having finished the rats, began 
to eat up the poultry and young birds of various 
kinds. As this went on the injurious insects and 
ticks, that the birds used to eat, began to gain 
the ascendant. A recent report—which requires 
confirmation—says that the increase of ticks is 
making life a burden to the mongooses. Thus a 
balance will be again arrived at. There is no 
doubt of that, but how much is often unnecessarily 
lost by the way! 


1 “ Presidential Address, Proc. Linnean Society N.S. Wales ” 
(1908), vol. xxxiii. pp. 1-38. 





CHAPTER III 
THE STRUGGLE FOR EXISTENCE 


67 








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CHAPTER III 


THE STRUGGLE FOR EXISTENCE 


The Idea not so Simple as it seems—The Anthropomorphism of 
the Idea—Different Forms of the Struggle for Existence— 
Struggle for Existence in the Plant World—Illustration of the 
Complexity of the Struggle for Existence—Reasons for the 
Struggle for Existence—Results of the Struggle for Existence— 
Breadth of the Darwinian Concept of the Struggle for 
Existence—The other Side of the Struggle for Existence— 
Mutual Aid—Application of the Concept to Human Life. 


THE IDEA NOT SO SIMPLE AS IT SEEMS.—No evolu- 
tionist phrase 1s more familiar than “ the struggle 
for existence,” which has passed into everyday 
usage. Yet it is not easy to grasp its full meaning, 
or to keepit vividly in mind. “ Nothing is easier,” 
Darwin said, “‘ than to admit in words the truth 
of the universal struggle for life, or more difficult— 
at least I have found it so—than constantly to 
bear this conclusion in mind. Yet, unless it be 
thoroughly engrained in the mind, the whole 
economy of nature, with every fact on distribution, 
rarity, abundance, extinction, and variation, will 
be dimly seen or quite misunderstood.” * 

If a recognition of the “ struggle for existence ” 
is essential to a clear outlook on nature, and 
if Darwin found difficulty in bearing it constantly 
in mind, we must be prepared to take some pains 
in trying to get a grasp of the facts which the 


1 «The Origin of Species,” p. 49, 
69 


70 DARWINISM AND HUMAN LIFE 


phrase sums up. This is the more desirable since 
there is often tyranny in a phrase, especially when 
it is misunderstood. Are we sure that we under- 
stand what the struggle for existence means ? 
Are we clear that it means much more than the 
bare words suggest? Do we understand that 
the phrase is a biological formula which has at 
the same time the misfortune of being an anthro- 
pomorphic metaphor ? 

From ancient days there had been a recognition 
of a struggle in nature—we find the idea expressed 
by Aristotle and by Lucretius, and more definitely 
by several of the pioneers of modern evolution 
theory—but it was Darwin who first realised its 
length and breadth, its height and depth, and, 
what is more, its dynamic significance. 

THe ANTHROPOMORPHISM OF THE IpEA.—In 
trying to understand the past and present of 
living creatures naturalists have followed with 
some success two very different methods, which 
seem opposed to one another, but are rather 
complementary. The one method is to inquire 
into the material machinery of vital activity, to 
throw on the puzzling drama of life the light of 
chemistry and physics. This is a sound method 
as far as i goes. The celery is blanched because 


1 It is interesting to notice how often Tennyson turns to certain 
aspects of the struggle for existence, as when he speaks of Nature 
“red in tooth and claw with ravine,” “So careless of the single 
life,” or in the well-known lines: 


** Tor life is not as idle ore ; 


But iron dug from central gloom, 
And heated hot with burning fears, 
And dip’t in baths of hissing tears, 

And batter’d by the shocks of doom 


To shape and use.” 


THE STRUGGLE FOR EXISTENCE 71 


it is hidden from the light; the child is pale 
because, roughly speaking, it has not enough of 
iron in its blood. The defect of the method is 
that, unless its partiality be borne in mind, it 
is apt to give a false simplicity to the facts, for 
it 18 quite certain that we cannot at present re- 
describe vital happenings in terms of modern 
physics and chemistry—vitalistic as these are. 
The old materialism has been found out. 

The other method is to read man into the 
beasts and even into the flowers of the field, to 
interpret the life of animals and plants in terms 
of human life. This is also a sound method as 
far as wt goes. Its defect is that, verification 
being difficult, we are apt to land in fanciful an- 
thropomorphism. Perhaps we may say, without 
cisrespect, that it was in great part Darwin’s 
method, just as the other was Spencer’s. Darwin 
approached the naturalist’s problem from above, 
Spencer from below. 

No better illustration of Darwin’s wholesome 
anthropomorphism can be found than the cardinal 
idea of the struggle for existence. It is an idea 
borrowed from human life; it was consciously 
suggested to Darwin by reading Malthus; it was 
subconsciously suggested by the keen industrial 
competition, more striking—because more novel— 
in Darwin’s day than in ours. In human life 
the phrase “ struggle for existence’ is a formula 
summing up in three words half the misery and 
half the happiness of mankind. It means that 
when Nature has said to man “ you must die” 
he has always answered back “I will live.”! It 
means that he has fought with wild beasts and 

1 See “The Kingdom of Man,” by Sir E. Ray Lankester. 


72 DARWINISM AND HUMAN LIFE 


worsted them or tamed them, that he has sifted 
out the wholesome from the poisonous plants, that 
cowering and crouching for ages, he has watched 
the forces of nature till he has mastered their 
secrets, that he has been to his fellows since the 
beginning the strangest mixture of self-assertiveness 
and sympathy, that he has kept up an age-long 
endeavour after well-being—always at his best 
when rowing hard against the stream. 

The formula, “ struggle for existence,” familiar 
in human affairs, was used by Darwin in his 
interpretation of organic life, and he showed that 
we gain clearness in our outlook on animate 
nature if we recognise there, in continual process, 
a struggle for existence not merely analogous 
to, but fundamentally the same as that which 
goes on in human life. He projected on organic 
life a sociological idea, and showed that it fitted. 
But while he thus vindicated the relevancy and 
utility of the sociological idea within the biological 
realm, he declared explicitly that the phrase 
“struggle for existence” was meant to be a 
shorthand formula,’ summing up a vast variety 
of strife and endeavour, of thrust and parry, of 
action and reaction. The idea has been better 
realised by naturalists than by the severer labora- 
tory specialists. “‘ It was certainly no chance,” 
Weismann says, “that the struggle for exist- 
ence first revealed itself to men who had spent 
the greater part of their lives in the open air.” 
Similarly, Prof. Poulton suggests that the main 
reason why Huxley never appreciated the theory 

1 «For words are wise men’s counters—they do but reckon by 


them; but they are the money of fools.” Hobbes, “‘ Leviathan,” 
Pt. L ch. iy, 


THE STRUGGLE FOR EXISTENCE 73 


of natural selection was that he had so little of 
the naturalist’s mood and experience. 

DIFFERENT ForMS OF THE STRUGGLE FOR 
HiXISTENCE.—Some of Darwin’s successors have 
taken pains to distinguish a great many different 
forms of the struggle for existence, and this 
kind of analysis is useful in keeping us aware of 
the complexities of the process. Darwin himself 
does not seem to have cared much for this logical 
mapping out and defining; it was enough for 
him to insist that the phrase was used “in a 
large and metaphorical sense,” and to give full 
illustrations of its various modes. For our present 
purpose it is enough to follow his example. 

(a) Struggle between Fellows.—When the locusts 
of a huge swarm have eaten up every green thing 
they sometimes turn on one another. This canni- 
balism among fellows of the same species—illus- 
trated, for instance, among many fishes—is the 
most intense form of the struggle for existence. 
An eerie struggle occurs between sister embryos 
in the egg-capsules of the buckie and the dog- 
whelk on the sea-shore. This sort of thing has 
its close analogue in what goes on between thick- 
sown seedlings of the same kind, which compete 
with one another for room and food and light. 
The struggle does not need to be direct to be 
real—the essential point is that the competitors 
seek after the same desiderata of which there is 
a limited supply. Whether an adult frog eats 
a tadpole of its own kind, or a female spider 
her suitor, or coral polyps compete for the same 
niche, or rabbits for the same scanty food, the 
formula is the same in all cases, and, apart from 
chance, the result will be the same—the survival 


74 DARWINISM AND HUMAN LIFE 


of those fittest for the particular conditions. 
The struggle may be for food, or foothold, or 
breathing-space, or what is sought after may be 
a luxury, as is seen in the wild stampede of the 
reindeer when the longing to visit the salt sea- 
shore becomes irresistible—many are overthrown 
and trampled in the mad rush. Here may be 
included the struggle for mates—the battles of the 
stags and the capercailzies, or the tournament of 
the blackcock at sun-rise on the hills. 

As an instance of keen struggle between nearly re- 
lated species, Darwin referred to thecombats of rats, 
but the case is not conclusive. The black rat (Mus 
rattus) probably came to Britain from Southern ports, 
and it was for many centuries the only kind of rat in 
‘Britain. Whenthebrownrat(Musdecumanus)came 
on the scene (probably from Baltic ports in the 
eighteenth century), the black rat had 1n part to give 
way before it, though there is no evidence of the 
internecine warfare which has been widely credited. 
The facts are carefully discussed by Dr. Chalmers 
Mitchell in his ‘‘ Evolution and the War ” (1915). 

(6) Struggle between Foes.—In the locust swarm 
and in the crowded cradle of young whelks there is 
competition between fellows of the same species, 
but the struggle for existence includes much 
wider antipathies. We see it between foes of 
entirely different nature, between carnivores and 
herbivores, between birds of prey and small 
mammals. In both these cases there may be a 
stand-up fight, for instance between wolf and 
stag, or between hawk and ermine; but neither 
the logic nor the biology of the process is different 
when all the fight is on one side. As the lem- 
mings, which have over-populated the Scandinavian 


THE STRUGGLE FOR EXISTENCE 75 


valleys, go on the march they are followed by 
birds and beasts of prey, which thin their ranks. 
Moreover, the competition between species need 
not be direct; it will come to the same result 
if both types seek after the same things. The 
victory will be with the more effective and the 
more prolific. 

In the same way we pass from the struggle of 
similar seedlings in the over-crowded garden-plot 
to the struggle of coarser with finer grasses after 
a veldt-fire—in many cases apparently ending in 
the survival of the coarsest. 

(c) Struggle with Fate-——Our sweep widens still 
further, and we pass beyond the idea of competition 
altogether, to cases where the struggle for existence 
is between the living organism and the inanimate 
conditions of its life—for instance, between birds 
and the winter’s cold, between aquatic animals 
and changes in the water, between plants and 
drought, between plants and frost—in a wide 
sense, between Life and Fate. 

THE STRUGGLE FOR EXISTENCE IN THE PLANT 
Worip.—We may be saved from taking a narrow 
view of the struggle for existence if we emphasise 
the fact that the concept must apply to plants 
as much as to animals. “It has always pleased 
me,’ Darwin said, “ to exalt plants in the scale 
of organised beings,” and in his books “ The 
Power of Movement in Plants,” “ Climbing 


1 We cannot here pursue the suggestive idea that, besides struggle 
between individuals, there is struggle between groups of individuals 
—the latter most notably developed in mankind. Similarly, 
working in the other direction, there is struggle between parts 
or tissues in the body, between cells in the body, between equiva- 
lent germ-cells, and, perhaps, as Weismann pictures, between the 
various multiplicate items that make up our inheritance. 


76 DARWINISM AND HUMAN LIFE 


Plants,” and ‘“ Insectivorous Plants,’ we find 
most interesting evidence that they are not so 
sound asleep as is often thought. Among the 
insectivorous plants we find actively aggressive, 
almost militant, forms, like the well-known Venus 
Fly-trap and the Sundew. Do they struggle 
less really than the octopus? Has not the Venus 
Fly-trap more than a hint of memory? Yet 
how impossible to draw the line where aggres- 
siveness ceases! We have to include the pas- 
sive pitcher-plants and_bladderworts. Apart from 
actually carnivorous plants there are various 
orchids that entrap, or, we may almost say, 
visibly resent certain intruding insects, and there 
are many common plants that have deep moats 
where unwelcome visitors drown, hedges of hairs 
where they are entangled, sticky surfaces where 
they are limed. 

There is no bloodshed among plants, but there 
is over-crowding, crushing, starving, smothering, 
strangling. Whether we take two lichens—each 
a quaint partnership of Alga and Fungus—com- 
peting for room to grow on an exposed stone, 
or the plants in the meadow, or the weeds in 
the sluggard’s garden, or the crowded life of the 
jungle, we find clear evidence of competition for 
space and light, for food and air. This has been 
beautifully expressed by R. L. Stevenson, in his 
poem “ The Woodman ” : 


Thick round me in the teeming mud 

Brier and fern strove to the blood: 

The hooked hana in his gin 

Noosed his reluctant neighbours in: 

There the green murderer throve and spread, 
Upon his smothering victims fed, 


THE STRUGGLE FOR EXISTENCE 77 


And wantoned on his climbing coil. 
Contending roots fought for the soil 
Like frightened demons: with despair 
Competing branches pushed for air. 
Green conqu ors from overhead 
Bestrode the bodies of their dead : 
The Cesars of the sylvan field, 

Unused to fail, foredoomed to yield: 
For in the groins of branches, lo! 

The cancers of the orchid grow. 

Silent, as in the listed ring, 

Two chartered wrestlers strain and cling; 
Dumb as by yellow Hooghly’s side 
The suffocating captives died ; 

So hushed the woodland warfare goes 
Unceasing ; and the silent foes 
Grapple and smother, strain and clasp 
Without a cry, without a gasp. 

Here also sound Thy fans, O God, 
Here too Thy banners move abroad : 
Forest and city, sea and shore, 

And the whole earth, Thy threshing-floor ! 
The drums of war, the drums of peace, 
Roll through our cities without cease, 
And all the iron halls of life 

Ring with the unremitting strife. 


But as we continue our illustrations of struggle 
among plants we lose the competitive note alto- 
gether,—in cases like the desert plant with- 
standing exceptional drought, and the northern 
plant withstanding unusually keen frost. No one 
doubts that extremes of drought and cold, and 
the like, press upon the ceaseless endeavour of 
even vegetable life, and that the plants answer 
back. They do not take every assault lying 
down. 

ILLUSTRATION OF THE COMPLEXITY OF THE 
StRuGGLE ror Existence.—To convey a broad 


78 DARWINISM AND HUMAN LIFE 


impression of the struggle for existence we 
cannot do better than refer to a graphic picture 
drawn by Mr. W. H. Hudson in his charming 
Naturalist in La Plata.” The summer of 1872-3 
in La Plata was rich in sunshine and showers ; 
there was great wealth of blossom; the humble- 
bees were very abundant; and the season was 
also very favourable for mice which devoured the 
bees. “In autumn the earth so teemed with 
mice that one could scarcely walk anywhere 
without treading on them; while out of every 
hollow weed-stalk lying on the ground dozens 
could be shaken.” They were so abundant that 
“the dogs subsisted almost exclusively on them ; 
the fowls also, from incessantly pursuing and 
killmg them, became quite rapacious in their 
manner ; whilst the sulphur tyrant-birds (Pitangus) 
and the Guira Cuckoos preyed on nothing but 
mice.’ The cats became wild hunters; ‘“ foxes, 
weasels, and opossums fared sumptuously ; even 
for the common armadillo (Dasypus villosus) it 
was a season of affluence.” Countless numbers 
of storks and of short-eared owls came to assist 
at the general feast. The owls were so numerous 
that any evening after sunset Mr. Hudson could 
count forty or fifty hovering over the trees about 
his house. They became destructive to birds as. 
well as mice, and although the naturalist shot 
many to try to reduce the havoc they were making 
among the ovenbirds, the gaps he made were so 
rapidly filled that he grew sick of the cruel war 
in which he had hopelessly joined. “ A singular 
circumstance was that the owls began to breed 
in the middle of winter.” “By August (1873) 
the owls had vanished, and they had, indeed, 


THE STRUGGLE FOR EXISTENCE ~ 79 


good cause for leaving. The winter had been 
one of continued drought; the dry grass and 
herbage of the preceding year had been consumed 
by the cattle and wild animals, or had turned 
to dust, and, with the disappearance of their 
food and cover, the mice had ceased to be.” The 
cats sneaked back to the houses. “ It was pitiful 
to see the little burrowing owls; for these birds, 
not having the powerful wings and_ prescient 
instincts of the vagrant Otus brachyotus, were 
compelled to face the poverty from which the 
others escaped.”’ They became tame with hunger, 
and so reduced as scarcely to be able to fly. 

Fine weather, ready cover, and plenty of food 
had allowed the mice to multiply beyond measure, 
but their enemies had likewise increased. As 
the herbage disappeared, multiplication of mice 
ceased, and the army of enemies cleared off the 
residue so thoroughly that “in spring it was 
hard to find a survivor, even in barns and houses.”’ 

This ‘“ wave of life” is one of the most in- 
structive of biological pictures. It illustrates the 
web of life, and the variety of the struggle for 
existence. A physical change lets the stream of 
life overflow, and, as the flood gathers momentum, 
it widens the breach in its banks. One struggle 
causes another struggle. Flowers abound, bees 
abound, mice abound, cats and owls abound, and 
there is struggle amongst all. Diets are changed, » 
habits are changed, numerical proportions are 
changed, and then the season changes and all 
is over. The mice are reduced to a minimum 
and the wave of life is lost in the sand. 

“The fact,” Mr. Hudson says, “that species 
tend to increase In a geometrical ratio makes 


80 DARWINISM AND HUMAN LIFE 


these great and sudden changes frequent in many 
regions of the earth; but it is not often they 
present themselves so vividly as in the foregoing 
instance, for here, scene after scene, is one of 
Nature’s silent, passionless tragedies open before 
us, countless myriads of highly organised beings 
rising into existence only to perish almost im- 
mediately, scarcely a hard-pressed remnant re- 
maining after the great reaction to continue the 
species.” 

REASONS FOR THE STRUGGLE FOR HXISTENCE.— 
The reasons for the struggle for existence among 
animals and plants are fundamentally the same 
as those which lie behind our own human struggle 
and endeavour. ‘“‘ Why do the people thus strive 
and cry ?”’ Goethe asked, and gave the answer, 
“They will have food, they will have children, 
and bring them up as well as they can.” So it 
is with other living creatures—their twofold, 
never-ending business is to care for themselves 
and to care for others. It has been said that 
hunger and love solve the world’s problems, and 
this is true if we take a wide enough view of these 
notable words. 

(a) One reason for struggle is to be found in the 
tendency to over-population. The river of life 
is always tending to overflow its banks. Struggle 
is the safety-valve against the internal pressure 
of rapidly increasing population. Wallace quotes 
Kerner to the effect that a common British weed 
(Sisymbrium sophia) often has three-quarters of 
a million seeds; if all grew to maturity for only 
three years the whole of the land-surface of the 
globe would not hold them. An annual plant 
with only two seeds would be represented by 


PLATE V 





LIFE-HISTORY OF THE COMMON FROG. 


The plate shows the adult frog, below that the developing frog-spawn, below that 
the newly-hatched larve hanging to the water-weed by means of adhesive organs, 
below that a larva with external gills. To the left are two later stages of tadpoles, 
the upper one about two months old. At the edge of the pool there is a young frog 
which has almost completed the absorption of the tail, 


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THE STRUGGLE FOR EXISTENCE 81 


1,048,576 in the twenty-first year. “A bacillus 
less than x o5yth of an inch in length multiplies, 
under normal conditions, at a rate that would 
cause the offspring of a single individual to fill 
the ocean to the depth of a mile in five days ” 
(H. E. Crampton). “ The cholera bacillus can 
duplicate every twenty minutes, and might thus 
in one day become 5,000,000,000,000,000,000,000, 
with the weight, according to the calculations of 
Cohn, of about 7,366 tons. In a few days, at this 
rate, there would be a mass of bacteria as big 
as the moon, huge enough to fill the whole ocean ” 
(R. C. Macfie). 

The slowest breeder among mammals is the 
elephant; it is supposed to rear one young one 
every ten years, but, as it lives to more than a 
hundred, Darwin calculated that in 750 years each 
pair would, if all their offspring lived and bred, 
be the ancestor of nineteen millions. The lemmings 
in the Scandinavian valleys become periodically so 
numerous that they eat up every plant, and must 
march or starve. The bands become an army which 
devastates as it goes, till their problem is solved 
in the waves of the Baltic or the North Sea. 

A cod has two million eggs, they say ; if these all 
developed into cods there would soon be no more 
fishing. An oyster may have sixty million eggs, 
and the average American yield is sixteen millions. 
If all the progeny of one oyster survived and 
multiplied, its great-great-grand-children would 
number sixty-six with thirty-three noughts after 
it, and the heap of shells would be eight times the 
size of the world. 

Huxley calculated that if the descendants of a 
single green-fly all survived and multiplied they 

6 


82 DARWINISM AND HUMAN LIFE 


would, at the end of summer, weigh down the 
population of China. 

The common house-fly lays eggs in batches of 
120 to 150 at a time, and may lay five or six of 
these batches during its life—of about three weeks 
in very hot weather. At the end of summer, if all 
developed, and if there were six generations, the 
progeny of a single pair, pressed together into a 
solid mass, would occupy a space of something like 
a quarter of a million cubic feet, allowing 200,000 
flies to a cubit foot. There is no real increase, 
hence the mortality must be prodigious. 

The intensity of the struggle can be inferred 
from the rate of increase. If there is slow multi- 
plication and yet no falling off in the number of 
adults, there is no keen struggle for existence. If 
there is rapid multiplication and yet no increase 
in the number of adults, there must be a keen 
struggle for existence. It is useful to thmk over 
the simple equation: the number produced minus 
the number eliminated equals the normal number 
of adults. 

(b) Another reason follows from the pattern of 
the web of life—there are nutritive chains, one 
organism depending on another for its food-supply. 
Indeed, the struggle that strikes us most is that 
which follows from the obvious fact that many 
animals prefer to be carnivorous. There is a good 
deal of the conjugation of the verb “ To eat” in 
life, and the objection to be eaten is as natural 
to some animals as the desire to eat is to others. 

(c) A third reason for struggle is to be found 
in the irregular changefulness of the physical 
environment. Give an animal time, and it may 
become marvellously well adapted to its surround- 


THE STRUGGLE FOR EXISTENCE — 83 


ings, as hand to glove; but when the surroundings 
change the adaptation is gone. In some cases, 
indeed, the living creature is adapted to change 
with the changes of its surroundings: turning white 
in winter, for instance, like the mountain-hare and 
the ptarmigan. But when the outer world changes 
wregularly, then the shoe pinches. The living 
creature must accept defeat or struggle, and its 
struggle may bring it success until a constitutional 
variation in the right direction has time to establish 
itself. 

(d) Another reason for struggle is often over- 
looked—namely, the self-assertiveness of the 
vigorous animal. The lusty creature tends to be 
a hustler. It elbows its way through the crowd, 
jostling its neighbours. Even the plant pushes 
and obstructs, ensnares and strangles, stings and 
kills. 

RESULTS OF THE STRUGGLE FOR HXISTENCE.— 
There are three chief results of the ubiquitous 
struggle for existence. 

(A) In the first place, there may be a reduction 
in numbers which relieves the pressure of popula- 
tion without directly making for progress. Out 
of 533 larvee of the large garden white butterfly 
collected by Prof. Poulton, 422 died from ichneu- 
mon grubs: four out of every five—a great 
mortality. But since there was no evidence that 
the survivors were saved by being the possessors of 
some peculiarity which those eliminated lacked, the 
thinning had no evolutionary importance. It was 
merely fortuitous or indiscriminate elimination. 

(Bs) In the second place, it may be that the 
organism is driven, by the pressure of the struggle, 
to seek out a new habitat, to choose a more appro- 


84 DARWINISM AND HUMAN LIFE 


priate environment, or, what comes to the same 
thing, to form a new habit. From the beginning, 
necessity has been the mother of invention. For 
animals, as for man, the exploration of new terri- 
tory has been a constantly recurrent result of the 
struggle for existence, and one of the most im- 
portant. The open-air naturalist 1s familar with 
the way in-which nearly related species fill slightly 
different corners in the same crowded area. It is 
interesting, also, to think of the gradual peopling of 
strange habitats, such as the abysses of the ocean, 
the dark caves, and under the ground; or how 
fishes come ashore, and mammals get into the air, 
and crabs go up the mountains. 

(c) In the third place, there may be discriminate 
elimination of the less fit to the given conditions, 
and it is this result that has most evolutionary 
interest. The interest is not so much in the fact 
that the carnivore devours the herbivore as in the 
possible sifting of the ranks of the herbivores by 
the elimination of the dull and the sluggish. A 
species may give rise to a variety which actually 
supplants the parent species, as in the case of one 
of the Sugar-Birds of the West Indies, but few 
cases are known where it can be said that this 
comes about by direct competition. When one 
species is more successful than another and sup- 
plants it, ‘“‘ we feel sure,’ Darwin said, “that the 
cause lies as much in one species being favoured 
as in another being hurt.” The alternative title 
of “ The Origin of Species by Means of Natural 
Selection ’’ was “The Preservation of Favoured 
Races in the Struggle for Life.” 

It is very important to realise that the struggle 
for existence may select without rapidly killing off 


THE STRUGGLE FOR EXISTENCE — 85 


the less fit. Ifit mean that the less fit have a more 
difficult life and do not live so long, if it mean that 
they have smaller and less vigorous families, if it 
mean that the parents are harassed so that they 
cannot give the offspring the best available start, 
then it will, in the long run, work out to the same 
result as if the less fit had come to a rapid violent 
end. The advantageous character that the fit 
variant possesses may be of survival-value, although 
the absence of it does not mean the sudden death 
of the less fit. 

The elimination of the less fit may have a con- 
servative influence, without resulting in any pro- 
gressive change. It may keep the race up to an 
established standard. But this is precisely the 
same kind of process as that which results in 
progressive adaptation, and should not be separated 
off. It need hardly be said that when we find a 
state of affairs where slackness is tolerated, it 
means a temporary resting on the oars. Among 
434 toads taken from the same place, Prof. W. E. 
Kellicott found 5 per cent. with injuries and 3°68 
per cent. with abnormalities, mostly disadvantage- 
ous. The conditions of life were peculiarly easy, 
there was abundant food, there were few enemies, 
there were readily available means of protection 
and concealment. 

BREADTH OF THE DARWINIAN CONCEPT OF THE 
STRUGGLE FOR ExisteNnce.—There are many au- 
thorities who insist that what Darwin particularly 
and mainly meant was the struggle between 
organisms of the same kind. Thus Weismann’ 
writes: The “struggle for existence,’ which 


1 “Darwin and Modern Science.” Edited by A. C. Seward, 
Cambridge (1909), p. 20 


86 DARWINISM AND HUMAN LIFE 


Darwin regarded as taking the place of the human 
breeder in free nature, is not a direct struggle be- 
tween carnivores and their prey, but is the assumed 
competition for survival between individuals of 
the same species, of which, on an average, only 
those survive to reproduce which have the greatest 
power of resistance, whilst the others, less favour- 
ably constituted, perish early.”’? 

Here, however, as in not a few other instances, 
Darwin is broader than many Darwinians. AI- 
though one of the sections in chapter ui. of 
“The Origin of Species ’’ is headed “ Struggle for 
Life most Severe between Individuals and Varieties 
of the same Species,” the evidence given hardly 
justifies the title, and, in any case, another section 
is headed ‘‘ The Term, Struggle for Existence, used 
in a Large Sense.” In writing to Hooker in 1856, 
he said: “ The slight differences selected, by which 
a race or species is at last formed, stand in a far 
more important relation to its associates than to 
external conditions”; but there are many passages 
n “The Origin of Species’’ which express the 
view that the struggle for existence as the method 
of Nature’s sifting includes very much more than 
internecine competition between fellows. “I should 
premise,”’ he says, “ that I use this term [“‘ struggle 
for existence ”’| in a large and metaphorical sense, 
including dependence of one being on another, 
and including (which is more important) not only 
the life of the individual, but success in SE 
progeny.” 

1 The same view is expressed by Haeckel and Ray Lankester, 
but I am glad to find that, in his scholarly and judicial ‘‘ Handbook 
of Darwinism,” Prof. L. Plate interprets Darwin’s conclusions 
and the state of affairs in nature in much the same way as I have 
done. 


THE STRUGGLE FOR EXISTENCE _ 87 


The position which we are seeking to define and 
defend is this. The concept “ struggle for exist- 
ence” is wider than is suggested by the words 
taken literally. It is a function of many in- 
dependent variables. It expresses the reaction of 
living creatures to ther limitations and difficulties. 
It means that living is rarely drifting, except for 
parasites. ‘The physical world is careless of life; 
there is an extraordinary abundance of life; the 
river is always surging up to its embankments ; 
love calls, hunger calls, and there is often no satis- 
faction ; there are many critical moments in growth 
and development, many risks of falling through 
holes in the Mirza bridge; the living creature has 
a will of its own—a will to live,—all this, and 
more, maybe usefully condensed in the formula 
“ struggle for existence.” 

Our thesis is that we have the struggle for exist- 
ence wherever living creatures press up against 
limiting conditions ; wherever living creatures, with 
their powers of growing and multiplying, thrusting 
and parrying, changing and being changed, do in 
any way say, “ We will live.” 

The living creature is by its very essence asser- 
tive. Ifit cannot do anything else it will multiply. 
Life is an endeavour; it expands, it intrudes itself, 
it protests against limitations. One living creature 
presses upon another, competes with another, eats 
another. And for all this thrust and parry between 
living creatures and their limitations we use the 
formula-phrase “struggle for existence.” Surely 
Darwin had this broad conception vividly in mind 
when he used that strange metaphor: ‘ Nature 
may be compared to a surface on which rest 
ten thousand sharp wedges touching each other 


88 DARWINISM AND HUMAN LIFE 


and driven inward by incessant blows ’’—the idea 
being that any wedge that was relieved from 
blows would at once rise above the rest. But 
the comparison to wedges is inadequate; we 
have to think of living wedges with a will of 
their own—a will to rise, and then we have got 
nearer the idea of the struggle for existence. 
The same idea is suggested by Darwin’s extra- 
ordinary sentence: “It may metaphorically be 
said that natural selection is daily and hourly 
scrutinising throughout the world the slightest 
variations.” | 

THE OTHER SIDE OF THE STRUGGLE FOR Exist- 
ENCE.—If we are right in our wide interpretation 
of the concept “struggle for existence,’ which 
we maintain to be Darwin’s, though many biolo- 
gists, such as Sir H. Ray Lankester, say it is not, 
then we can pass in a more logical way than here- 
tofore to what has sometimes been called the other 
side of the struggle for existence: to a recognition of 
the love of mates, parental sacrifice, filial affection, 
the kindliness of kindred, gregariousness, sociality, 
co-operation, mutual aid, and altruism generally. 
These are facts of life, though we may differ as to 
the precise psychological terms to be used in 
describing them. The business of life, all through, 
includes care for others as well as care for self. As 
Herbert Spencer says: “If we define altruism as 
being all action which, in the normal course of 
things, benefits others instead of benefiting self, 
then, from the dawn of life, altruism has been no 
less essential than egoism. Though primarily it 
is dependent on egoism, yet secondarily egoism 
is dependent on it.” “ Self-sacrifice is no less 
primordial than self-preservation.” As has been 


THE STRUGGLE FOR EXISTENCE 89 


well said: “The purely self-seeking animal has 
been found to be a fiction, like that of the 
economic man” (Norman Wilde). 

Our position is that, instead of making an anti- 
thesis between “ struggle for others ” and “ struggle 
for self,” it is clearer to recognise that both may be 
included in the rubric of reaction of self-assertive 
living creatures against the difficulties and limita- 
tions of environing conditions. In many cases a 
kin-instinct is as well defined as a self-preservative 
instinct, and, in face of difficulties and limita- 
tions, a solution may be found along either line 
or along both. The world is indeed the abode 
of the strong, but it is also the home of many 
feeble folk who make up in love what they lack 
in strength. 

Mutvuat Atp.—Kropotkin has done real service 
to science by showing, in detail, how much there 
is of mutual aid among animals. There are some 
genuine societies, where the whole is more than the 
sum of its parts and sometimes acts as a unity. 
Ants are little people, and all the world is against 
them; in facing their limitations—which is what 
“ struggle’ means—they have found a solution 
in sociability, and they are dreaded by much 
stronger insects. Every one knows that some 
species of ants go to war. But our outlook on 
nature should take its colour not only from the 
wartare, but also from the self-subordination which 
the whole life of the ant-hill illustrates. In many 
species it seems to be a law of the hill that an ant 
with a full crop must never refuse to feed a hungry 
comrade. 

There is something very suggestive in an ob- 
servation of Hudson’s in regard to social and 


90 DARWINISM AND HUMAN LIFE 


sociable animals higher up in the scale, the Vis- 
cachas—burrowing rodents of South America. 
When the farmer destroys a viscacha burrow and 
buries the inhabitants under a heap of earth, other 
viscachas, coming from a distance—for village 
often visits village—dig out those that are buried 
alive. There are thousands of similar facts, which 
go to show that there is much more in the animal 
world than a Hobbesian warfare—each for himself 
and extinction take the hindmost. 

Besides animal societies in the stricter sense 
there are many flocks and herds—gregarious rather 
than social creatures; and what we know of their 
mode of life, though it is not nearly so precise as it 
ought to be, warrants us in saying that the vul- 
garisation of the Darwinian picture of the struggle 
for existence is inaccurate. There is an ugly 
proverb which says that a wolf is a wolf to other 
wolves, but Kipling’s zoology is finer: there’s a 
law of the pack which means self-subordination. 
We do not associate kites and vultures with fine 
feelings, but the Brazilian kite is said to summon 
its friends to the feast (when it is big enough), and 
one of the strongest vultures is called—not without 
good reason—the sociable vulture. 

There are instances of co-operation among 
animals neither social nor gregarious; thus a dozen 
burying beetles may combine to transport a dead 
bird to soft ground. Every one knows that little 
birds, like wagtails, will combine to drive off a falcon, 
and there are many records of the frequent disap- 
pointment of birds of prey when they visit the 
lake-side crowded with ducks and terns and 
plovers. It is quite certain that the battle is not 
always to the strong. Another striking fact is the 


THE STRUGGLE FOR EXISTENCE 91 


social character of migration in the case of many 
birds that usually live alone. 

Besides sociality, gregariousness, and co-opera- 
tion, there are the associations of the pair and the 
family, which evidently include much more than 
squabbling round the platter. The struggle for 
existence includes, as Darwin emphasised, “ suc- 
cess In leaving progeny.” Macgillivray found two 
thousand feathers in the nest of the long-tailed tit. 

It goes without saying that mutual aid pays, 
and pays because there is a universal struggle for 
existence. Wedo not wish, therefore, to complicate 
the issue with psychological questions of egoism 
and altruism, self-regarding and other-regarding ; 
nor do we wish to make an antithesis between 
mutual aid and mutual struggle ; our point is that 
within the wide concept of Struggle—or Reaction to 
Limitations—there is encluded mutual aid, and that 
this mode of solution is attended with success—a 
success which is more than survival, for it spells 
progress as well. As Kropotkin says: “ Mutual 
aid leads to mutual confidence, the first condition 
for courage, and to individual initiative, the first 
condition for intellectual progress.” The intel- 
ligence of the social birds, like rooks, parrots, and 
cranes, has been the subject of admiration since 
natural history began. 

Let us get away from mere words and into 
contact with facts. Animals get hungry, they 
seek their food, they endeavour to catch what often 
endeavours not to be caught, they compete with 
others who endeavour to catch the same elusive 
prey, they have also to keep an eye on those who 
are seeking to catch them while they are seeking 
to catch something else, and meanwhile they have 





92 DARWINISM AND HUMAN LIFE 


to struggle to keep their foothold amid the storm 
of the careless physical environment. There are 
also struggles for mates and for the sake of off- 
spring. Which of these endeavours is the struggle 
for existence ? Hach and all. For the real mean- 
ing of the phrase is to be found, not in picturing 
this or that kind of struggle or endeavour, but 
rather in the general idea of living organisms 
asserting themselves against limitations and diffi- 
culties, partly no doubt due to their immediate 
competitors of the same kin or even family, but 
by no means restricted to this. 

Our thesis is that progress depends on much 
more than a squabble around the platter; that the 
struggle for existence 1s far more than an inter- 
necine competition at the margin of subsistence ; 
that it includes all the multitudinous efforts for self 
and others between the poles of love and hunger ; 
that it comprises all the endeavours of mate for 
mate, of parent for offspring, of kin for kin, as well 
as every detail of self-assertiveness ; that existence 
for many an animal means the well-being of a 
socially bound or kin-bound organism in a social 
milieu ; that egoism 1s not satisfied until it becomes 
altruistic. 

APPLICATION OF THE ConcEPT TO HumAN Lirks. 
—What has the Darwinian conception of the 
struggle for existence to do with human life ? 

(1) If Nature has any particular word to say 
to man that word is Endeavour. All through the 
ages we may see Nature’s condemnation of “ the 
unlit lamp and the ungirt loin.” Nature is all for 
efficiency, and down on slackness. 

(2) It has to be admitted, however, that, at 
juncture after juncture, Nature offers the alterna- 


THE STRUGGLE FOR EXISTENCE 93 


tive of parasitism, and there are thousands of living 
creatures that have followed this line of least re- 
sistance with its reward of adult safety and complete 
material well-being, with its nemesis of degeneracy. 
To man also this alternative is offered, and it is 
not infrequently, in part at least, accepted, both 
by lower and by higher stocks, and always with 
inevitably attendant dangers. Let us recall Mere- 
dith’s verse : 


Behold the life of ease, it drifts. 

The sharpened life commands its course $ 
She winnows, winnows roughly, sifts, 

To dip her chosen in her source. 

Contention is the vital force 

Whence pluck they brain,—her prize of gifts. 


(3) As among animals, so among men, disturb- 
ances of equilibrium and conflict of interests bring 
about struggle, and there are always two chief lines 
of solution (besides that of partial parasitism). 
The one is increased intensity of competition ; the 
other is increased combination and mutual aid. 
From the biologist’s point of view it 1s important 
to make clear that Nature has rewarded both these 
lines of solution with survival, and that the line 
of mutual aid and sociality has been especially 
justified by psychical progress. We may take it 
that, as it has been in the past, survival and pro- 
gress will continue to be the rewards of those 
nations in which there is not only valour in com- 
petition (more and more shifted from the battle- 
fields), but the virtue of loyal subordination of 
individual to communal interests. 

(4) With the spread of civilisation the character 
of the struggle for existence among men _ has 


94 DARWINISM AND HUMAN LIFE 


greatly changed, becoming less and less literal, less 
and less sustained. It is seldom allowed to work 
out to a finish, as it does in the animal world. As 
this is apt to result in a state of affairs in which 
the superior are defrauded of the rewards of superi- 
ority and the inferior are not mulcted for their 
inferiority—an unnatural state of affairs—it be- 
hoves man ‘to secure that the literal struggle for 
existence is replaced by an endeavour after 
well-being, which will continue in a subtler, more 
rational, more humane form the automatic singling 
and sifting which goes on in Nature. 


CHAPTER IV 


THE RAW MATERIALS OF 
EVOLUTION 


95 





CHAPTER IV 


THE RAW MATERIALS OF EVOLUTION 


Organic Progress Primarily depends on Variability—Darwin’s Posi- 
tion—Progress since Darwin’s Day in Regard to Variation— 
Variations more Abundant than even Darwin supposed— 
Proportion between Frequency and Amount of Variations 
—Correlation of Variations—Brusque Variations more Frequent 
than was formerly supposed—Discontinuous Variations— 
Mutations—Darwin’s Position in Regard to Mutations—Origin 
of Variations—Germinal Selection—Variational Stimuli— 
Modifications or Acquired Characters—Indirect Importance of 
Modifications — Modification-Species — Individual Plasticity— 
Relation to Human Life. 


OrGANIC PRroGRess PRIMARILY DEPENDS ON 
VARIABILITY.—The most difficult problem in bio- 
logy—part of the persisting mystery of life itself— 
is the innate changefulness which we often see 
manifested in a family, a herd, or a seed-plot, when 
we compare one generation with another. Of how 
much interest and importance is this changefulness ! 
for it is among the inborn variations of living 
creatures that we find the raw materials of evolu- 
tion. 

Evolution implies change—change along a defi- 
nite line, and it also implies a certain continuity 
throughout the change. Individual development, 
the growing of the mustard-seed into the greatest 
of herbs, the “ minting and coining of the chick 
out of the egg,” is progressive change in which the 

97 7 


98 DARWINISM AND HUMAN LIFE 


continuity is one of personal identity. In organic 
evolution the continuity is racial, not individual ; 
but, as in development, there is progress in the wide 
sense. It may be up or down, for the better or for 
the worse, measured by certain standards, but 
progress of some sort 1s implied in the concept of 
evolution, and it is with the raw materials of 
progress that we are now concerned. The interest 
of this inquiry is enhanced by the fact that, through- 
out the ages, life has been on the whole slowly 
on the upgrade, and that among animals there has 
been a gradual emergence of greater control and 
more freedom, of a fuller life and higher intelligence. 

Darwin's Posirion.—Darwin started from the 
admitted fact of life that offspring are often 
innately different from one another and from 
their parents. Through his study of species— 
which began in his boyish beetle-collecting and 
went on to his eight years’ work on barnacles— 
he had become aware of the fountain of change 
in living creatures, and he strengthened his 
impression by patiently accumulating facts in 
regard to the variability of domesticated animals 
and cultivated plants. In his original 1858 essay, 
and in the “ Origin of Species ” (1859), he recog- 
nised two kinds of hereditary variations: (1) large 
“single variations,” or “ sports,’ which occur 
rarely and result in individuals conspicuously 
different from the type of the species; and (2), 
slight ‘‘ individual variations,’ which are of 
frequent occurrence, distinguishing child from 
parent, brother from sister, or cousin from cousin. 
He was much interested in the large single varia- 
tions, such as occurred in the origin of copper-beech 
and weeping willow, but—true to the influence 


THE RAW MATERIALS OF EVOLUTION 99 


of Lyell—he came to the conclusion that the 
minute ubiquitous “ individual variations ” were 
by far the more important. Fleeming Jenkin, 
Professor of Engineering in Edinburgh, pointed 
out that single large peculiarities would be likely 
to be swamped by inter-crossing, and this criticism 
had so much weight with Darwin that he ceased 
to attach importance to the larger divergences, 
and found his raw material in what he called 
“individual variations.” “‘The more I work,” 
he said, “the more I feel convinced it is by the 
accumulation of such extremely slight variations 
that new species arise.” 

In reference to both sports and small variations, 
Darwin used the terms “ indefinite” and “ spon- 
taneous,” to distinguish them from “ definite 
variations,” which are now called somatic modifica- 
tions—.e. definite and direct results of environ- 
mental or functional changes. Darwin believed 
in the occasional transmissibility of these “ definite 
variations,’ and in so doing he agreed with 
Lamarck, whose work he does not seem to have 
adequately appreciated. 

PRoGRESS since Darwin’s Day In REGARD TO 
VARIATION.—While we must still confess, with 
Darwin, that in regard to the causes of variation 
our ignorance is immense, we have also to recognise 
that, in several directions, there is progress to 
report. For some time after the publication of 
“The Origin of Species”? more attention was 
given to the directive than to the orrginatie factors 
in evolution. The idea of selection fascinated 
naturalists, and 1t was too much the custom simply 
to postulate variability to meet the demands of 
particular problems. Life is so abundant and 


100 DARWINISM AND HUMAN LIFE 


so Protean that biologists tended to draw upon 
the variability account as if there was no limit 
to it, scarce waiting to see whether their cheques 
were honoured. A lesson might have been taken 
from Darwin’s painstaking study (1868) of varia- 
tions in domesticated animals and cultivated 
plants, or from Mr. J. A. Allen’s pioneer work 
(1871) in measuring American birds, but the 
vice of simply postulating variations when they 
were wanted for theoretical purpose persisted 
for half a century and still lingers. 

In the preface to his ““ Materials for the Study 
of Variation ” (1894), Bateson wrote: “ We are 
continually stopped by such phrases as, ‘if such 
and such a variation then took place and was 
favourable,’ or, “we may easily suppose circum- 
stances in which such and such a variation, if 
it occurred, might be beneficial,’ and the like. 
The whole argument is based on such assumptions 
as these—assumptions which, were they found 
in the arguments of Paley or of Butler, we could 
not too scornfully ridicule. . . . If we had before 
us the facts of variation there would be a body 
of evidence to which, in these matters of doubt, 
we could appeal. We should no longer say ‘ Jf 
variation take place in such a way,’ or ‘Jf such 
a variation were possible’; we should, on the 
contrary, be able to say, ‘Since variation does, 
or at least may, take place in such a way,’ 
‘Since such and such a variation is possible,’ 
and we should be expected to quote a case, or 
cases, of such occurrence as an observed fact.” 

In the most general terms it may be said that 
one of the greatest steps of progress in evolution- 
lore since Darwin’s day has been the accumulation 


THE RAW MATERIALS OF EVOLUTION 101 


of accurate data in regard to the variations that 
do actually occur. It is a tedious task, but 
peremptorily necessary, and already it is having 
its reward. The recording and statistical registra- 
tion of variations—such as we find in the pages 
of the journal called Biometrika—is rapidly helping 
us out of the slough of vagueness, in which, to 
the physicist’s contempt, biology is so apt to 
flounder. Let us try to state some of the general 
impressions that we get from the post-Darwinian 
study of variation. 

(1) Variations more Abundant than even 
Darwin supposed.—* Even Darwin himself,’ as 
Wallace says, “did not realise how much and 
how universally wild species vary”; but one of 
the clear results of much patient work of recent 
years has been the proof that variations are as 
marked among creatures living wild in nature 
as they are among those under man’s control. 
The fountain of change is even more copious 
than was dreamed of. 

In commenting on the “ fallacy of the belief 
that great variation is much rarer in wild than 
in domesticated animals,’ Mr. Bateson notes 
that “‘ if we examine the variation in the vertebre 
of the sloths, in the teeth of the anthropoid 
apes, in the colour of the dog-whelks (Purpura 
lapillus), etc., we find a frequency and a range of 
variation matched only by the most variable of 
domesticated animals.” We get the same im- 
pression when we look at a good collection of 
cuckoo’s eggs, or of land-snails, or of ruffs, and 
so on through a long list. 

It is difficult to realise the frequency and amount 
of variations until one begins to measure and 


102 DARWINISM AND HUMAN LIFE 


weigh. In 1871 Mr. J. A. Allen measured numerous 
individual representatives of some common species 
of American birds, and found that, as regards 
important points, eg. length of bill and length 
of wing, birds of the same sex and season, caught 
at the same place, on the same day, showed 
numerous variations, often large in amount. “ The 
facts of the case,’ Mr. Allen says, “ show that 
variation of from 15 to 20 per cent. in general 
size, and an equal degree of variation in the relative 
size of different parts, may be ordinarily expected 
among specimens of the same species and sex 
taken at the same locality, while in some cases 
the variation 1s even greater than this.” 

(2) Proportion between Frequency and Amount 
of Variations.—Another fact has been made clear 
in regard to variations: there is a proportion 
between the frequency of a _ particular change 
and the amount of its departure from the mean 
of the character in question. In other words, 
the variations, when plotted out, show what is 
called the Curve of Frequency of Error. In 


1 Quetelet (1846) showed that variation followed the law of 
frequency of error, the mathematical expression of which was 
discovered by Gauss. Sir John Herschel, in illustrating this, took 
the case of a rifleman aiming at a target. “It was pointed out 
that, irrespective of the skill of the rifleman, the shots, after a 
large number of trials, would be aggregated most thickly about 
the centre of the target, and would be more and more thinly scat- 
tered the farther the distance became from the centre of the target. 
The only difference between the targets of a good and of a bad 
rifleman is that in the former case the total area which contains 
all the shots would be smaller than in the latter case. But in 
each case the centre of the area would coincide with the centre 
of the target, and the distribution of shots within the area would 
be similar. The explanatien of this result rests upon the cir- 
cumstance that, each time the rifleman takes aim, a number of 
factors come into operation, tending to disturb the correctness 


THE RAW MATERIALS OF EVOLUTION 103 


measurements of 2,600 men, taken at random, 
Wallace notes that there is 1 of 4 ft. 8 in. and 
1 of 6 ft. 8in.; 12 of 5 ft. and about 12 of 6 ft. 4 in. ; 
equal numbers at equal distances from the mean 
of 5 ft. 8 in. 

If the variations of a particular character in a 
population of animals in a given area be plotted 
out year after year and the curve show a con- 
sistently increasing skewness, we may infer that 
the stock is evolving in a definite direction as 
regards the character measured. Similarly the 
formation of a double-humped curve may vividly 
bring home the fact that the species is dividing 
into two sub-species. Thus, by a statistical path, 
we are brought face to face with the most vital of 
all facts—l’évolution créatrice. 

(3) Correlation of Variattons.—Another im- 
pression which we get from some of the modern 
work on variation is, that the living creature 


of the alignment of the rifle. But as these factors act with equal 
frequency in every direction, it follows that the point of thickest 
distribution of the shots will still remain at the centre of the target. 
Now, variation is found to follow precisely the same law. If measure- 
ments of some character are taken in a large number of individuals, 
it is found that there is a mean measurement in the neighbourhood 
of which the individuals are most thickly clustered, and that the 
further the distance from the mean, the fewer are the individuals 
represented. The analogy goes yet farther: for, just as in the 
ease of the good and bad riflemen, we found the shots to be in 
close juxtaposition or more widely scattered, so in the case of 
variation, it is found that the divergences from the mean are in 
some cases far more accentuated than in other cases; that is to 
say, the degree of constancy or variation in different organs is 
very different. But in all cases the variation can be represented 
by a geometrical curve, the ordinates of which are proportional 
to the terms in the expansion of the binomial (a+b). Occasionally 
the individuals are found to cluster round two or more points of 
thickest distribution, and it is then inferred that they belong to 
two or more different races.”—Hdinburgh Review, Jan. 1909. 


104 DARWINISM AND HUMAN LIFE 


varies, in many cases, aS a unity, not in this 
corner and that—like a machine that 1s perfected 
by the accumulation of little patents,—but through 
and through and all at once. As Darwin pointed 
out, there is a “ correlation of variations.”? One 
change brings another in its train, and the one 
that is for the time most important may evolve 
another much more important. Thus a variation 
too small in itself to be of value may be carried 
over the dead point into effectiveness because it 
is physiologically bound up with another variation. 

Another aspect of the same idea is that what 
seem to be new departures in widely separated 
parts of the animal may be really diverse outcrops 
of one deep physiological change. We may have 
thought of this in connection with some disease 
that we have watched: it has very different 
expressions in different parts of the body, though 
it is due to a single slight derangement in the 
normal sequence of chemical events. We may 
have thought of the same idea in connection 
with sex, where changes apparently confined 
to minute and superficial and unconnected parts 
may be, as it were, the correlated outcrop of 
one deep physiological change.’ It 1s a familiar 
fact that numerous apparently distant and un- 
connected changes of adolescence are all funda- 
mentally one. Similarly, when an individual plant 
or animal varies as a whole, when compared with 
its parent, this means that the potential individual, 
the germ-cell, has varied as a unity. 

(4) Brusque Vareations more Frequent than 
was formerly supposed.—But the most important 


1 “ The Evolution of Sex,” by P. Geddes and J. Arthur Thomson, 
«Contemporary Science Series ” (1889). Revised Edition (1901). 


THE RAW MATERIALS OF EVOLUTION 105 


general result of the modern study of variability 
is the evidence that changes of considerable 
amount sometimes occur at a_ single leap. 
These brusque changes are called ‘“ discontinuous 
variations,’ and, in certain cases, ‘‘ mutations.” 
Lamarck said, “‘ Nature is never brusque,” and 
we usually look askance at reports of “ Jack-in- 
the-Box ” phenomena in nature; but, through the 
solid work of Bateson, De Vries, and others, there 
is more reason to-day than there was fifty years 
ago to believe that organic structure may pass 
with seeming abruptness from one position of 
organic equilibrium to another. 

Discontinuous VartatTions.—In the individual 
development of an embryo there is gradual con- 
tinuous change from hour to hour, from day to day ; 
and if we suppose similar changes to occur, not as 
normal stages in the development of one creature, 
but as new steps of progress in successive genera- 
tions of creatures, we have the individual variations 
that Darwin most believed in as furnishing the 
raw materials of evolution. Butin many a develop- 
ment, such as that of a starfish or a butterfly, 
there 1s In a certain sense discontinuity ; there is a 
crisis, when the developing creature recommences 
on a new track; and thissort of change occurring, 
not as a normal event in individual development, 
but as a new departure in racial evolution, would 
be a “discontinuous variation.” Using Galton’s 
simile, we can picture a polyhedron oscillating or 
rocking on one of its faces: this would be an 
** individual variation,’ or fluctuation ; we can also 
picture it rolling over to a position of equilibrium 
on another face: this would be “ discontinuous 
yarlation,”’ or mutation, 


106 DARWINISM AND HUMAN LIFE 


The greatest contribution in this connection is 
Bateson’s work entitled, ‘ Materials for the Study 
of Variation,’ which showed that discontinuous 
variations of certain kinds are not uncommon. 
Abundant evidence is given of “the existence of 
sudden and discontinuous variation ; the existence, 
that is to say, of new forms having from their first 
beginning more or less of the kind of perfection 
that we associate with normality.” 

Murations.—The idea that the Proteus may 
leap as well as creep 1s prominent in the work of 
the Dutch botanist De~ Vries, embodied in his 
‘“‘ Mutations-Theorie.”’ De Vries tells the story, for 
instance, of a stock of the evening primrose 
(Hnothera lamarckiana), which he found as an 
escape in a potato-field near Amsterdam. It was, 
as it were, frolicking in its freedom ; “ sporting,”’ as 
we say. Almost all its organs were varying, as 
if swayed by a restless, internal tide. It showed 
minute fluctuations from generation to generation ; 
it showed extraordinary freaks, such as fasciation 
and pitcher-forming; it showed hesitancy as to 
how long it meant to live, for while most were 
biennial, many were annual, and a few were 
triennial ; best of all, it showed what seemed like 
new species in the making. From this stock De 
Vries obtained, in a short time, halfa dozen or more 
distinct varieties or elementary species, breeding 
true generation after generation. He was led to 
the important conclusion that “ new varieties are 
produced from existing forms by sudden leaps.” 

Like other evening primroses, @nothera lamarck- 
cana is of American extraction, and a happy dis- 
covery in the Paris herbarium of a specimen 
collected in North America in the eighteenth 


PLATE Vi 


A ps4, 


A; 


ua 


‘ 
N 
\ 
\ 
AY 
NY 





EXAMPLES OF VARIATIONS. 


A. A medusoid, Hpenthesis folleata. a. Another form, Pseudoclytia pentata, which 
has probably arisen as a pentamerous mutation of A (after A. G. Mayer). B.A potato 
beetle, Leptinotarsa multiteniata, var. rubicunda; b. Another, L. multiteniaia, var. 
melanothorax. Both are mutations of the typical L. multiteniata (after W. L. Tower). 
C. Typical frond of Hart’s Tongue Fern, Scolopendrium vulgare ; c. The variety stans- 
fieldvi (after Lowe). D. and d. Two varieties in the pattern of the abdomen in the 
Yellow-Jacket Wasp (after Kellogg and Bell), 


106} 








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THE RAW MATERIALS OF EVOLUTION 107 


century shows that it was just one of the many 
wild species of that country. ‘This disposes of the 
objection that the mutations of this type may be 
the results of a mixed ancestry. 

The first part of the Dutch botanist’s great work 
was published forty-three years after “ The Origin 
of Species,” and there are many who regard the 
Mutation Theory and Mendelism as the two 
greatest steps of progress that have been made 
in evolution-lore since 1859. 

The general idea is that novel characters may 
suddenly appear, as it were, full-fledged, with con- 
siderable perfectness from the moment of their 
emergence, and without intergrades linking them to 
the parents. Furthermore, the novel character of 
the mutant, if we may use the word, is independently 
heritable and does not blend; it can be grafted 
intactly on to another stock, or it can be dropped 
out as such. Again, mutations are what may be 
called qualitative, as contrasted with the fluctua- 
tions which are quantitative. Thus, some of the 
new evening primroses which De Vries got out 
of his changeful stock of Gnothera lamarckiana 
were very different from the parent type—some had 
few branches instead of many, some had small 
flowers instead of large, some had quite different 
leaves, and so on. Mutations have been recorded 
for other species of evening primrose and for various 
plants, such as shepherd’s purse and snapdragon. 
Some striking instances of a sudden change of 
character have been reported by bacteriologists, 

Among animals in nature we know as yet of few 
sudden emergences of qualitatively new characters, 
but several cases have been reported. Thus pink 
katydids may abruptly appear among green ones, 


108 DARWINISM AND HUMAN LIFE 


and short-winged insects in a long-winged race, 
in both cases without intergrades. A black mutant 
of the peppered moth (Amphidasys betularia) ap- 
peared near Manchesteraboutthe middle of the nine- 
teenth century and has been very successful. A 
black mutant of one of the West Indian Sugar-Birds 
(Ceereba) has almost supplanted the parent species. 

When we turn, however, to domesticated animals, 
where we have greater opportunities of intimate 
observation, the case for mutation becomes 
stronger. There are sudden negative changes— 
the entire dropping out of a character—as seen in 
the abrupt appearance of hornless cattle, sheep, and 
goats, of hairless dogs and horses, of tailless cats 
and dogs. ‘There are also sudden positive changes 
—the acquisition of a new character—such as the 
appearance of extra digits in poultry and pigs. 
Those who have bred birds are familiar with such 
sports, which are often striking. There is evidence 
in a number of cases that stable and successful 
breeds have been established, not by the slow 
increase of minute fluctuations, but by getting a 
big start ina mutation. In many cases, although 
breeding or cultivation has grafted the novelty on to 
a strong stock and made it prepotent, it has not 
greatly increased the magnitude of the quality 
which the original sport exhibited. 

Darwin’s Position In RecarD To Mutations. 
—Though Darwin had not the conception of unit 
characters—that is to say, independently heritable 
characters which are handed on intact or dropped 
out altogether—in its modern clear-cut form, he 
was well acquainted with mutations in domesticated 
animals and cultivated plants, and he dismissed 
most of them as not important. In the first place, 


THE RAW MATERIALS OF EVOLUTION 109 


they seemed to him to partake too much of the 
pathological. But we must not hurriedly dismiss 
mutations like that of fowls with webbed feet and 
no tails as obviously teratological, for most of 
them may be matched in nature. If there were 
only one specimen of a cross-bill, for instance, 
would it not be regarded as a freak which could not 
possibly survive in nature? In the second place, 
reacting as he was against a catastrophic view of 
nature, and looking at things (as he said) through 
Lyell’s! eyes, Darwin naturally fought shy of 
big sudden changes. Moreover, as he said to Asa 
Gray: “ There seems to me in almost every case 
too much, too complex, and too beautiful adapta- 
tion in every structure to believe in its sudden 
production.”’ Finally, he thought that a full- 
fledged new character appearing suddenly would 
be swamped by intercrossing.’ 

The last difficulty, which is the only serious one, 
has been removed, for it is characteristic of muta- 
tions that, when they arrive, they come to stay, 
unless they be eliminated as disadvantageous. In 


1 It was characteristic of the Lyellian, or Uniformitarian school 
of geologists to explain large results on the principle of slow suc- 
cessive increments, accumulating for a very long time. 

2 Let us hear what he says in the last edition of “ The Origin 
of Species”’ : 

‘* Mr. Mivart is further inclined to believe, and some naturalists 
agree with him, that new species manifest themselves ‘ with sudden- 
ness and by modifications appearing at once....’ This con- 
clusion, which implies great breaks or discontinuity in the series, 
appears to me improbable in the highest degree” (p. 201). 

“Although very many species have almost certainly been 
produced by steps not greater than those separating fine varieties, 
yet it may be maintained that some have been developed in a 
different and abrupt manner. Such an admission, however, 
ought not to be made without strong evidence being assigned ”’ 
(p. 203). 


110 DARWINISM AND HUMAN LIVE 


other words, a new unit character of a beetle or 
of a shepherd’s purse—two experimentally tested 
instances—does not blend when its possessor is 
crossed with the original type. It is not swamped 
by intercrossing, but reappears in its integrity in 
a definite proportion of the succeeding generations. 
Already in actual practice in wheat-growing it is 
being found that selected single ears breed true, 
and that no further selection is needed. 

The attractiveness of the mutation theory is so 
great that we must be particularly cautious in our 
acceptance of it. It would relieve the difficulties 
that many naturalists have in believing that the 
apparent big lifts and qualitative changes which 
the history of organic life implies have arisen by 
the natural selection of minute individual fluctua- 
tions. It would make more intelligible the dis- 
continuity of many species, if we found reason to 
believe in their saltatory origin. It need hardly 
be said that the origin of the mutation would 
remain a mystery, for the mutation theory is not 
a theory of mutations. It will be interesting if 
evidence accumulate to show that the Proteus 
leaps as well as creeps, if future generations look 
back to Darwin as the naturalist who saw nature 
moving by small steps, while De Vries caught a 
glimpse of her dancing ! 

OricIN oF VarraTions.—In regard to the difficult 
question of the origin of variations, we must not be 
impatient to answer until our knowledge of their 
nature has greatly increased. We must still confess, 
with Darwin: “ Our ignorance of the laws of varia- 
tion is profound. Not in one case out of a hundred 
can we pretend to assign any reason why this or 
that part has varied.” And again he said: 


THE RAW MATERIALS OF EVOLUTION 111 


“Tf, as I must think, external characters produce 
little direct effect, what the devil determines each 
particular variation ? ” 

Having made this confession of ignorance, we 
venture to discuss the possibilities of answer to a 
question which can never be far from any thought- 
ful mind. 

There are variations and variations. There are 
variations that mean nothing more than an aug- 
mentation or diminution of an already existing 
quality. The hair may be very long or the tail 
very short. Or a variation may mean that a 
character present in parents and ancestry is absent 
from the offspring: the entail has been broken. 
An albino expresses such a variation, or a hornless 
calf, or a tailless kitten. Or, again, a variation 
may be interpretable as a novel arrangement of 
characters or qualities which were present in the 
ancestry. A piebald pony may serve as a diagram. 

Now, in regard to variations of this sort— 
which may be described as permutations and 
combinations of the already existing unit char- 
acters—the modern knowledge of the conditions 
of heredity has made it plain that there are many 
opportunities for their occurrence before, during, 
and after fertilisation. We know that each germ- 
cell contains a definite number of stainable bodies, 
or chromosomes, which appear to be the bearers 
of the heritable qualities. We may compare these 
to a microscopic pack of cards, and we may say 
that there is an extraordinarily elaborate shuffling 
before development begins. Half of the pack is 
ejected from the egg-cell in what is known as a 
“polar body,” and the number is raised to the 
normal again (constant throughout the body of the 


112 DARWINISM AND HUMAN LIFE 


organism) by the entrance of the fertilising sperma- 
tozoon whose chromosomes have also been reduced 
by a half. In fertilisation, at the beginning of 
each new life, there is an intricacy of combination 
that may be likened to the making of a living 
mosaic out of parental and ancestral contributions. 
It may also be that in the making of the germ- 
cells there is a segregation of antithetic qualities, 
so that two diflerent kinds of germ-cells result, 
corresponding to the two sharply contrasted 
parents. It may also be, as Weismann supposes, 
that there is a strugglé between rival unit-char- 
acters in the penetralia of the germ-cells. In 
any case, there 1s abundant opportunity for new 
permutations and combinations. There are many 
factors which may give the vital kaleidoscope a 
twist. 

There is, however, another kind of variation, 
when novel features appear, which are qualitative 
rather than quantitative, substantive rather than 
architectural, in kind rather than in degree, and 
more than mere rearrangements of previously 
expressed unit characters. What can be said as 
to their origin ? 

Weismann and others have suggested that 
the stimulus to germinal variations comes from 
the oscillations and changes in the immediate 
surroundings of the germ-cells. They get their food- 
supply from the body, and that food-supply is 
liable to be somewhat variable. It may contain 
a poison, for instance, which seriously shakes 
the architecture of the germ-plasm at the very 
start; but it may also contain some stimulus, 
which provokes the living germ to a new de- 
parture. 


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THE RAW MATERIALS OF EVOLUTION 113 


Another suggestion, which has some interesting 
experimental evidence behind it, is that important 
changes in the environment—changes in chemical 
composition, heat, light, and electrical conditions, 
and so on—may saturate deeply through the 
body and stimulate the germ-cell to change. We 
shall return to this suggestion later on. 

GERMINAL SELEcTION.—In his theory of “ ger- 
minal selection’? Weismann elaborated a very 
interesting speculation in regard to the roots of 
variation. With his characteristic way of following 
an idea as far as it would lead him, he extended 
the concepts of struggle and selection to the 
primary constituents (or determinants) within 
the germ-cell. In consequence of unequal nutrition 
these primary constituents are always varying. If 
one of them, corresponding, let us say, to a sense- 
cell, receives for a considerable time more abundant 
food than before, it will grow in proportion, and 
if the germ-cell develops into an organism the 
sensory cell may be twice as strong as it was in 
the parent. 

But the strengthened determinant may begin 
actively to nourish itself more abundantly— 
attracting the food to itself, and in some measure 
withdrawing it from its fellow-determinants. In 
this way “it may get into a permanent upward 
movement, and attain a degree of strength from 
which there is no falling back.” 

In a similar manner a downward variation of 
a determinant may be started by diminished 
nutrition, and the weakened determinant will 
have less affinity for attracting nutriment because 
of its diminished strength. “If a certain critical 
stage of downward progress be passed, even 


8 


114. DARWINISM AND HUMAN LIFE 


favourable conditions of food-supply will no 
longer suffice permanently to change the direction 
of the variation.” 

If, in such a case, the determinant be that of 
a useful structure, then the ordinary process of 
natural selection will remove the individual; but 
if the weakened determinant be that of a useless 
organ it will continue getting weaker generation 
after generation. 

“In most cases the fluctuations will counteract 
one another, because the passive streams of 
nutriment soon change; but in many cases the 
limit from which a return is possible will be passed, 
and then the determinants concerned will continue 
to vary in the same direction till they attain 
positive or negative selection-value. At this stage 
personal selection intervenes and sets aside the 
variation if it is disadvantageous, or favours— 
that is to say, preserves—it if it is advantageous. 
But the determinant of a useless organ is un- 
influenced by personal selection, and, as experience 
shows, it sinks downwards; that is, the organ 
that corresponds to it degenerates very slowly 
but uninterruptedly till, after what must obviously 
be an immense stretch of time, it disappears from 
the germ-plasm altogether.” Thus “ germinal 
selection supplies the stones out of which personal 
selection builds her temples and palaces: adapta- 
Hons.o:- 

The theory is, of course, entirely hypothetical, 
dealing as it does with the invisible, but it enables 
us to formulate a large number of facts. 

VARIATIONAL STIMULI.—Some very interesting 
investigations point to the possibility of the germ- 


1 “The Evolution Theory,” by Weismann (1904), vol. ii. 


THE RAW MATERIALS OF EVOLUTION 115 


cells being influenced by stimuli from without. 
It has been shown experimentally that chemical 
substances in the food of the mother may be 
carried on into the offspring. Thus, when the 
dye known as Sudan is mixed with the food 
of hens, it appears in the yolk of the egg and 
eventually in the fatty tissue of the chick. Per- 
haps this sort of thing is commoner than is usually 
supposed. By changing the temperature and 
the food of the caterpillars of Vanessa and Arctia, 
Standfuss and Fischer were able to induce, in 
the next generation, aberrant characters, which 
remained distinct when crossed with the parent 
form. 

More striking, however, are the experiments 
carried on for twelve years by Professor Tower 
on beetles of the genus Leptynotarsa, which he 
subjected to unusual conditions of temperature 
and moisture when the male or female reproductive 
organs were at a fixed point in their development. 
The result was to induce in the offspring striking 
changes, not only in colour and markings, but 
also in some details of structure. Sometimes all 
the germ-cells seemed to be affected, sometimes 
only a fraction of them ; sometimes various changes 
resulted from the same treatment; some of the 
changes were brusque, others showed intergrades 
with the parental conditions; sometimes the 
change did not occur until after the lapse of 
several generations in the wnusual environment ; 
there was no reversion to the parental condition. 
Of course Tower could not get at the reproductive 
organs except through the body, but it should 
be noted that the body of the parent was not 
changed, and it was only at particular stages 


1146 DARWINISM AND HUMAN LIFE 


that the influence was operative. Here, then, we 
have definite evidence of germinal variation 
evoked by environmental stimulus. 

Very interesting, also, are the experiments of Dy. 
C. 8. Gager, who exposed the egg-cells and pollen- 
cells of Onagra biennis to Radium rays, and found 
that plants grown from the seeds produced under 
this influence were very different from the parents, 
and that the change persisted to the second genera- 
tion at least. Here, again, there is proof of heritable 
variation induced by environmental stimulus. 

Shortly before his death Darwin began to 
experiment on the possibility of producing galls 
artificially. ‘He imagined to himself wonder- 
ful galls caused to appear on the ovaries of 
plants, and by these means he thought it possible 
that the seed might be influenced, and thus 
new varieties arise.”? What Darwin just began 
has been carried out with great skill by Prof. 
D. T. MacDougal. “ Among other operations, 
solutions of sugar, calcium, potassium, and zinc 
were injected by the use of hypodermic syringes 
into the developing ovaries of Raimannia, one of 
the evening primroses, early in 1905, with the 
result that, out of several hundreds of seeds borne 
by the treated ovaries, sixteen individuals were 
found to be notably atypic, among other char- 
acters lacking the trichomes which are so con- 
spicuous with the parental form. These reproduced 
themselves in the second and third generations, 
coming true to the newly-assumed characters.” ? 
Similar experiments were made with Mnothera 


1 ** Life and letters of Charles Darwin,” vol. ii. p. 517. 
2«*The Direct Influence of Environment,” by D. T. Mac- 
Dougal, in ‘‘ Fifty Years of Darwinism” (1909), 


THE RAW MATERIALS OF EVOLUTION 117 


brennis and Penstemon wright, and we have 
decisive evidence that environmental stimulus 
acting directly on the germ-cells may induce 
striking variations. This is a very important 
result, for it is evident that the germ-cells of 
animals may in a similar way be naturally stimu- 
lated to vary by chemical changes in the vascular 
fluids. With the flowers, as with the beetles, there 
were not only losses and augmentations of what 
was previously present, but there were distinct 
novelties which maintained their distinctness when 
crossed with the parental strains. 

After we have worked for years along the lines 
of these various suggestions that have been offered 
as to the causes of variations, we shall be better 
able to say how far they account for what we believe 
has occurred in the past, and for what we know 
to occur at present. Perhaps they will prove 
insufficient, and evolutionists will be forced to 
recognise that variability is, like growth, a primary 
quality of living things, and that “ breeding 
true’ has arisen secondarily as a restriction. 
The relation of genetic continuity between succes- 
Slve generations 18 an economical arrangement 
which secures relative constancy amid continual 
flux, but in spite of this the Proteus continually 
asserts itself. Its essence is creative power. It 
lives because it changes, it changes because it 
lives. From generation to generation there is a 
continuous lineage of germ-cells; but just as we 
see a youth growing and changing, taking time 
into himself and making himself, in some ways, 
new by his experience, so it may be that there is a 
power of growing and varying inherent in the germ- 
cells—as also in the unicellular organisms in the 


118 . DARWINISM AND HUMAN LIFE 


waters—which requires only time and experience 
to produce what is new. 

MopIFICATIONS, OR ACQUIRED CHARACTERS.— 
We must now ask a very important question. Are 
there no other raw materials of evolution besides 
those inborn changes which we call variations and 
mutations, which we trace back to more or less 
mysterious processes occurring in the germinal 
material ? It is well known that our bodies suffer 
change according to what we do ordo not do, and 
according to climate and food, and so forth. Does 
this sort of change not furnish part of the raw 
material of evolution 2 

Among the observed differences which mark 
man from man, or trout from trout, or buttercup 
from buttercup, there are many to which we can- 
not apply the word “variation.” For, apart 
from constitutional or inborn changes, there are 
differences which are impressed upon the body 
in the course of life by mfluences from without, 
such as sun-burning in man or colour in trout; or 
by use and disuse, such as callosities on the fingers. 
These do indeed presuppose a constitution capable 
of being changed, but we can relate each to some 
definite influence, either of function or of environ- 
ment, which has brought about a structural change 
transcending the limits of organic elasticity. We 
call these modifications, and though they may be 
of much importance to the individuals possessing 
them, they are not known to be of any direct 
importance in the evolution of the race, for the 
sumple reason that there is no convincing evi- 
dence that they can be transmitted. Here the 
Lamarckians entirely dissent; but they have still 
to prove their case. 


THE RAW MATERIALS OF EVOLUTION 119 


After much discussion most naturalists have 
come back to the position of Kant, that life does 
not run on a-eompound interest principle of adding 
to the child’s inheritance the individual acquisi- 
tions (somatogenic or exogenous modifications) 
of the parents. As a matter of fact, we do not 
know of any clear case of individual modifications 
due to surroundings, education, work, or sloth, 
being transmitted in any degree to offspring. That 
the parents’ mode of life influences the children 
yet unborn is obvious; but the point is, whether the 
influence produces a corresponding or representa- 
tive effect. 

InprrEct Importance or Mopirications.— 
Those who find no warrant for accepting the 
Lamarckian postulate of the transmissibility of 
modifications, do not thereby assert that modifica- 
tions are of no importance. Many living creatures 
are exceedingly plastic, and their modifiability 
sometimes saves them where their variability is 
at fault. This idea has been elaborated independ- 
ently by Profs. Mark Baldwin, Lloyd Morgan, 
and H. F. Osborn, and we venture to quote 
Lloyd Morgan’s terse summary : 

(1) Variations (V) occur, some of which are in 
the direction of increased adaptation (+), others 
in the direction of decreased adaptation (-—). 
(2) Acquired modifications (M) also occur. Some 
of these are in the direction of increased accom- 
modation to circumstances (+), while others are in 
the direction of diminished accommodation (— ) 
Four major combinations are— 


(a) + V with + M. (c) — Vwith + M. 
(6) + V with — M. (d) — V with — M. 


120 DARWINISM AND HUMAN LIFE 


Of these (d) must inevitably be eliminated while 
(a) are selected. The predominant survival of 
(a) entails the survival of the adaptive variations 
which are inherited. The contributory acquisi- 
tions + M are not inherited; but they are none 
the less factors in determining the survival of the 
coincident variations.”’ Lamarckians believe that 
useful modifications are in some degree sometimes 
transmitted. On the view just sketched the modi- 
fications are the screens or nurses of coincident 
variations in the same direction. 

We can imagine conditions where swarthiness 
was a character of life-saving value, where the 
possessors of inborn variations in the direction of 
swarthiness were favoured, where those who varied 
in the direction of increased blondeness were 
handicapped. It is readily intelligible that those 
who could acquire swarthiness as an individual 
somatic modification would also be favoured, and 
that the acquired swarthiness might act as a life- 
saving screen until constitutional and _ heritable 
swarthiness had time to establish itself. 

Furthermore, although modifications may not 
be entailed, they may have occasionally important 
mdirect influences on the offspring. A starved 
mother may have a weakly child. 

MopIFICATION-SPECIES.—In the case of animals 
and plants which we do not know except in 
particular surroundings, it is quite possible that 
characters which we credit to inherited nature 
may be impressed on every successive generation 
by nurture. Especially among the more vegeta- 
tive forms of life we find indications, which experi- 
ment will some day test, that there are what may 
be called “ modification-species,” which differ from 


THE RAW MATERIALS OF EVOLUTION 121 


nearly related species only because the conditions 
of their life are different. 

INDIVIDUAL Puasticiry.—At all events, there 
is great interest in individual plasticity, n what 
can be effected by changes in nurture. We must 
picture the living creature as continually running 
the gauntlet of the mechanical, chemical, physical, 
and even animate influences that make up its 
environment. It passes over a series of anvils, 
on each of which the hammers ring a different 
tune. Let us take a few illustrations from among 
the many. 

If the alkalinity of the sea-water be slightly 
altered, the egg of a sea-urchin allows itself to be 
fertilised by the sperm of a starfish, or of a crinoid, 
or of a mollusc (!), producing larvee which all take 
after the mother. 

If the chemical and physical state of the sea- 
water be slightly disturbed, artificial partheno- 
genesis can be induced in starfish and sea-urchin, 
in worm and mollusc. 

Sometimes the result of a slight chemical change 
is very perplexing, and there are many experiments 
at which we look with bated breath. Quaint 
abnormal larvee of sea-urchin and frog are obtained 
by adding a lttle lithium to the water, and the 
addition of a létle magnesium to the sea-water 
containing embryos of the fish Pundulus hetero- 
chitus induces in a large number of these the de- 
velopment of a single Cyclopean eye in place of 
the normal two eyes.’ 

A small Crustacean called Gammarus, very 
common in fresh water, has the habit of avoiding 


1 Charles R. Stockard, in Journal of Experimental Zoology, 
February 1909. 


122 DARWINISM AND HUMAN LIFE 


the light, but add a little acid so that the solution 
is no stronger than 742 th of one per cent., and 
Gammarus swims towards the light. 

Remove one or two of the metals from sea- 
water, keeping up the alkalinity, and the sea- 
urchin egg develops into twins. Raising the 
temperature a little often has the same result. 

Cold slows growth and development, yet the 
population of floating and drifting animals is 
denser in the Arctic waters than in the Tropics— 
a curious fact which Prof. Loeb explains by showing 
that lowering the temperature greatly increases 
the duration of life. There are more generations 
living at the same time. Lowering the temperature 
of the caterpillar box may be followed by curious 
aberrations of colour in the moths and butterflies, 
especially in the direction of melanism (Standfuss, 
Fischer, and others). Prof. Poulton showed that 
the caterpillars of the small tortoise-shell, for 
instance, are for a short time so sensitive that 
those in a white or gilded box have light or 
golden pup, while those from the dark box have 
dark pupe. 

The influence of diet alone might form the subject 
of a course of lectures. Take the simple but very 
suggestive fact reported by Marchal that a scale- 
insect, Lecanium corni, becomes L. robintarum when 
reared on Robinia pseudoacacia instead of on its 
own normal food-plant, though the reverse ex- 
periment does not succeed. Or consider one of 
the most interesting of recent researches. Mr. 
C. W. Beebe! caused the scarlet tanager (Piranga 
erythromelas) and the bobolink (Dolichonyx oryz- 
vorus) to keep their breeding plumage through 

1 American Naturalist (1908), vol. xlii. p. 34. 


THE RAW MATERIALS OF EVOLUTION 123 


the year by giving them fattening food and keeping 
them without much exercise in dim light. Gradual 
return to the light and the addition of mealworms 
to the menu brought back the spring song, even 
in mid-winter. After a year, and at the beginning 
of the normal breeding season, individual tanagers 
and bobolinks were gradually brought under normal 
conditions and activities, and in every case they 
moulted from nuptial plumage to nuptial plumage, 
the dull colours of the winter season having been 
skipped. The inherited constitution determines 
what is possible, but there 1s evidently a large 
range of plasticity. We do not know that modifica- 
tions are entailed, but we must attach all the more 
importance to the influence of the environment in 
bringing about individual adjustment, in stimu- 
lating variation, and in punctuating developmental 
processes. 

ReLATIoN TO Human Lire.—-What has all this 
discussion regarding fluctuations and variations 
and mutations and modifications to do with 
human life? It would be easier to answer this 
question if we knew more about these changes, 
but some practical considerations are obvious. 

To begin with, man probably arose by a mutation; 
that is to say, by a discontinuous variation of 
considerable magnitude. Hvery one who has known 
a genius has in this happy experience some idea, of 
what is meant by a mutation, though the com- 
parison breaks down inasmuch as the quality of 
genius is rarely heritable. It is not merely that 
the genius has more brains; he has a new pattern 
of brains, and a large mutation is a new constitu- 
tional pattern. It is likely that man had his 
starting-point as a prepotent anthropoid genius. 


124 DARWINISM AND HUMAN LIFE 


Man’s origin is hidden, and, whatever our ancestry 
was, we cannot change it; man’s future is also 
hidden, but it will be, in some measure, of our 
making. Now, it is evident that some variations 
are undesirable: they make their possessor miser- 
able, and his neighbours hardly less miserable. We 
admit that there is an “ optimism of pathology ” ; 
unpromising buds may burst into flowers as fair as 
they are unexpected, weaklings bend Titans to their 
will, cripples make the world go round, and those of 
marred visage teach us what beauty really is; but, 
with all the breadth of view that biology will allow, 
there are some variations on which the verdict of 
history is that they make for retrogression. Every 
one wishes these variations to die out. 

There are other variations that are unmistakably 
desirable—in the direction of fine physique, 
artistic skill, keen mental ability, originality, 
socialised disposition, and strength of character. 
Every one wishes these variations to be widely 
distributed. 

Inquiry into the history of good animal stocks 
shows that steady progress has always rewarded 
the mating of nearly related forms, while the 
blending of distant and incompatible types seems 
often to lead to reversionary mongrels. Here we 
have a warning to the thoughtless experimenter 
with his own stock. 

One of the characteristics that should dis- 
tinguish the biologist is an expectancy, an open- 
mindedness, a tolerance, even a reverence, with 
respect to variations; for these new departures 
on the part of the ever-changing organism are the 
raw materials of progress, and should be sedulously 
guarded. Individuality is often born, often 


THE RAW MATERIALS OF EVOLUTION 125 


smothered, rarely made. A man with an idio- 
syncrasy, who is snubbed as an impossible person, 
may be a Moses who might have led us out 
of bondage! Captain Fitzroy nearly refused to 
take Darwin on the Beagle voyage because of 
his nose ! 

For various reasons biologists take a strong 
interest in the play of animals and of children. 
Play is no mere safety-valve for overflowing 
animal spirits: it 1s a rehearsal, without responsi- 
bilities, of some of the essential activities of adult 
hfe. But it is more: it affords what the Germans 
call Abdnderungspielraum—playground for varia- 
tions. The playing organisms are the most 
educable. 

The distinction between variations and modifica- 
tions seems sometimes academic and tiresome, but 
if we understand it we see it as one of the most 
practical of questions. Do the innate changes 
in the natural inheritance furnish the whole raw 
material of progress, or do the changes in the body 
due to peculiarities of nurture furnish some? At 
present the scientific answer seems to be, that the 
raw material of organic evolution is due to varia- 
tions, and in no direct way due to modifications. 

On the other hand, it has to be carefully borne 
in mind that hereditary nature and environmental 
nurture are complementary, not antithetic. The 
degree of development attained by any character 
depends upon the fulness and appropriateness of 
nurture. An inherent capacity for good or for 
evil may remain like a sleeping bud if the liberating 
stimuli of appropriate nurture be withheld. More- 
over, we know very little as yet in regard to 
the potency of nurture in prompting variability. 


126 DARWINISM AND HUMAN LIFE 


Another aspect to be considered is that unless 
environment evolve along with the organism the 
most promising new departures may be smothered 
by weeds. 

Of supreme importance is the commonplace 
that man differs from the beasts that perish in 
having a lasting external heritage to which age 
after age contributes. - There is social evolution 
as well as organic evolution, and social evolution 
has provided an apparatus whereby the gains of 
experience may swell the legacy of successive 
generations, although they do not, from the nature 
of the case, become part of the germinal inheritance. 

As Lloyd Morgan! well says: “ The history of 
human progress has been mainly the history of 
man’s higher educability, the products of which 
he has projected on to his environment. This 
educability remains, on the average, what it was 
a dozen generations ago; but the thought-woven 
tapestry of his surroundings is refashioned and 
improved by each succeeding generation.” 

“Few men have in greater measure enriched the 
thought-environment with which it is the aim of 
education to bring educable human beings into 
vital contact than has Charles Darwin.” 


1 “* Mental Factors in Evolution,” in ‘‘ Darwinism and Modern 
Science ” (1909), p. 445. 


CHAPTER V 
FACTS OF INHERITANCE 


127 





CHAPTER V 


FACTS OF INHERITANCE 


Progress during the Darwinian Era—Demonstration of Heritable 
Qualities—Heredity, a Term for the Genetic Relation between 
Successive Generations—Appreciation of Distinction between 
Nature and Nurture—The Idea of the Continuity of Genera- 
tions—Critical Attitude in Regard to Various Conclusions— 
Mendelism—Methods of Studying Heredity—Microscopical 
Study of the Germ-cells-—Statistical Study: Filial Regression 
—Galton’s Law of Ancestral Inheritance—Experimental Study 
—Pairing of Similar Pure-bred Forms—Blending—Particulate 
Inheritance—Exclusive Inheritance—Reversion—New Depar- 
tures—Mendelian Inheritance—Unit Characters—The Case 
of Andalusian Fowls—Waltzing Mice—Occurrence of Mendelian 
Inheritance—Practical Importance of Mendelism—Much 
Progress but Great Uncertainty—Transmission of Acquired 
Characters—Disease—Facts and Possibilities—A Striking Case 
—Logical Position of the Question—Cases where the Theory 
of Modification-inheritance is Inapplicable—Importance of 
Environment and Function Remains—Selection and Stimulus 
—Indirect Importance of Modifications—Practical Import of 
the Question as to the Transmission of Acquired Characters— 
Inheritance of Moral Character—Three General Conclusions. 


EVEN in ancient times men pondered over the 
resemblances and differences between children and 
their parents, and wondered as to the nature of 
the bond which links generation to generation; 
but, although a recognition of these problems is 
old, the precise study of them is altogether modern, 
and may almost be called Darwinian. [or it was 
largely through Darwin’s influence that the scientific 
study of heredity began. “ Before and after 
Darwin,” Professor Osborn says, “ will always be 
129 9 


130 DARWINISM AND HUMAN LIFE 


the ante et post urbem conditam of biological history”; 
so it may be useful to inquire into the advances 
that have been made in the study of heredity since 
the beginning of Darwin’s day.’ 

PROGRESS DURING THE DARWINIAN Hira. (1) 
Demonstration of Heritable Qualitves.—Before 1859 
much attention was given to the demonstration 
of the general fact of inheritance. In a large 
treatise like that of Prosper Lucas (1847) many 
hundreds of pages are devoted to proving, what we 
now take for granted—that our start in life 1s no 
haphazard affair, but rigorously determined by our 
parents and ancestors; that various peculiarities, 
important and trivial, useful and disadvantageous, 
reappear as part of the inheritance generation 
alter generation. 

This demonstration of heritability is still going 
on in reference to particular qualities; thus we 
have Prof. Karl Pearson’s evidence in regard to 
such subtle qualities as longevity and fecundity, 
and his indirect proof that mental qualities illus- 
trate the same law of inheritance as bodily qualities. 
It is very desirable that more data should be accu- 
mulated in regard to the heritability of variations, 
whether Darwin’s “ individual variations,’ or De 
Vries’s “‘ mutations.” On the whole, however, it 
may be said that, since Darwin’s day, sufficient 
evidence has been gathered to justify us I saying 
that any kind of character which appears as an 
inborn feature in an organism may be transmitted 
to the next generation. 

(2) “ Heredity” a Term for the Genetic Rela- 


1 See, for a detailed discussion of what is dealt with briefly in 
this chapter, the author’s treatise “ Heredity ” (2nd ed. Murray. 
London, 1912). ; 


FACTS OF INHERITANCE 131 


tion between Successive Generations.—Another step 
is, that we are learning not to spell heredity 
with a capital “h.’” We no longer think of it 
as a power or as a principle, as a fate or as 
one of the forces of nature; we study it as a 
genetic relation which is sustained by a visible 
material basis, as a relation of resemblances and 
differences which can be measured and weighed, or 
in some way computed. In regard to property 
there is a clear distinction between the heir and 
the estate which he inherits; but at the beginning 
of an individual life there is biologically no such 
distinction. The organism and its inheritance are, 
to begin with, one and the same. We inherit our- 
selves. Thus “heredity” is simply a convenrent term 
for the genetic relation between successive generations, 
and imheritance includes all that the organism is, or 
has, to start with wm virtue of its hereditary relation. 
(3) Appreciation of Distinction between “ Nature”’ 
and ‘ Nurture.’—Another step, following on 
the last, is that we have begun to realise more 
clearly the distinction implied in the words 
“nature” and “nurture”’—a distinction made 
by Shakespeare and definitised by Galton. The 
fertilised egg-cell contains, in some way which 
we cannot picture, the potentiality of a particular 
living creature—a tree, a daisy, a horse, a man. 
If this inheritance is to be realised there must be 
an appropriate environment, supplying food and 
oxygen and necessarystimuli of many kinds. With- 
out this nurture the inherited nature can achieve 
nothing. The development of every character 
implies the interaction of the two sets of factors— 
the internal organisation and the external environ- 
ment. But the surrounding influencesare often very 


132 DARWINISM AND HUMAN LIFE 


changeful, and the nature of the young organism 
may be profoundly modified by them. Thus we 
try to distinguish—and it is of enormous practical 
as well as theoretical importance—between the 
expression of hereditary nature realised in normal 
nurture and the individually acquired modifica- 
tions which are due to changes or peculiarities in 
that nurture. The characters of a newly hatched 
chick stepping out of the imprisoning egg-shell are 
in the main strictly hereditary ; but they need not 
be altogether so, for during the three weeks before 
hatching there has been some opportunity for 
peculiarities in the environment to leave their 
mark on the developing creature. Still more is 
this the case with the typical mammalian embryo, 
which develops often for many months as a sort of 
internal parasite within the mother, m a complex 
and variable environment. And as life goes on, 
peculiarities due to nurture continue to be super- 
imposed on the hereditary qualities, especially 
when the creature trades with time, and, by choosing 
its own nurture, creates for itself an individuality. 

(4) The Idea of the Contenucty of Generations. 
—Another step is the general acceptance of a 
somewhat subtle and yet essentially simple idea, 
which may be called the continwuty of genera- 
tions. There is a sense, Galton says, in which 
the child is as old as the parent, for when the 
parent's body is developing from the fertilised 
ovum a residue of unaltered germinal material is 


1 In his address “‘ Fifty Years of Darwinism,” Prof. Poulton says : 
‘“‘ The greatest change in evolutionary thought since the publication 
of the ‘ Origin’ was wrought, after Darwin’s death, by the appear- 
ance of that wonderful and beautiful theory of heredity, which 
jooks on parents as the elder brother and sister of their children.” 


FACTS OF INHERITANCE 133 


kept apart to form the reproductive cells, one of 
which may become the starting-point of a child. 
In many cases, scattered through the animal 
kingdom, from worms to fishes, the beginning of the 
hneage of germ-cells is demonstrable in very early 
stages before the division of labour implied in 
building up the body has more than begun. Let us 
suppose that the fertilised ovum has certain 
qualities, a, b, c,... x, y, 2; it divides and re- 
divides, and a body is built up; the cells of this 
body exhibit division of labour and the structural 
side of this, which we call differentiation; they 
lose their likeness to the ovum and to the first 
results of the cleavage of the ovum. In some of 
the body-cells the qualities a, b find predominant 
expression; In others the qualities y, z; and so 
on. But if, meanwhile, there be certain germ- 
cells which do not differentiate, which retain the 
qualities a, b, c,... 2, y, 2 unaltered, these will 
be in a position by-and-by to develop into an 
organism like that which bears them. Similar 
material to start with, similar conditions in which 
to develop—therefore, like tends to beget like. To 
use Weismann’s words: “In development a part 
of the germ-plasm (ze. the essential germinal 
material) contained in the parent egg-cell is not 
used up in the construction of the body of the 
offspring, but is reserved unchanged for the forma- 
tion of the germ-cells of the following generation.” 
Thus the parent is rather the trustee of the germ- 
plasm than the producer of the child. In a new 
sense, the child is a * chip of the old block.’ ” 

May we think for a moment of a baker who has 
a very precious kind of leaven ; he uses part of this 
in baking a large loaf; but he so arranges matters, 


134 DARWINISM AND HUMAN LIFE 


by a curious contrivance, that part of the original 
leaven is not mixed up with the dough, bus is 
carried on unaltered within the loaf, carefully 
preserved for use in another baking. Nature is 
the baker, the loaf is a body, the leaven is the germ- 
plasm, and each baking is a generation. 

Picture the long runner of a strawberry, bearing 
rooted, flowering plants at intervals: the runner 
may represent the continuous line of germ-cells, 
the flowering plants are the individuals, and the 
relation between them is the relation of genetic 
continuity, which we call heredity. 

It will be obvious that this concept of germinal 
continuity 1s very different from Darwin’s pro- 
visional hypothesis of pangenesis, according to 
which the germ-cells have their peculiar virtue of 
reproducing like from like because they become 
the storehouses of representative gemmules liber- 
ated from the various organs of the body. Although 
the hypothesis did not at the time obtain favour 
and is less acceptable now than ever, it is interesting 
to note, as Prof. Strasburger points out, that it in- 
cluded the favourite modern idea of invisible units 
as the carriers of particular hereditary characters. 

(5) Critical Attitude in regard to Various Con- 
clustons.—Another change is seen in the critical 
attitude which is now taken up in regard to 
various sets of facts, or alleged facts, relating to 
inheritance, which were once accepted without 
question. Thus Darwin said a good deal about 
reversion ; but many phenomena labelled “ rever- 
sion’ have received a different interpretation, and 
some of the leading authorities on heredity have 
ceased to use the term. It is difficult to find a 
scientific worker who believes in what many 


FACTS OF INHERITANCE 135 


practical men put money on—the influence of a 
previous sire on offspring subsequently borne 
by the same mother to a different father. More 
serious, however, is the wide-spread scepticism as 
to the transmission of individually acquired charac- 
ters or modifications. 

(6) Mendelism.—But the greatest change that 
has come about since Darwin’s day is the most 
recent ' one—associated with the work of Mendel. 
We shall devote some attention to this at a later 
stage In our exposition, but it may be noted, 
in the meantime, that Mendelian experiment 
has afforded evidence that an inheritance often 
consists, in part at least, of well-defined, non- 
blending “ unit characters.” ‘‘ By a unit character 
in the sense of Mendel’s law we mean any quality 
or part of an organism, or assemblage of qualities 
or parts, which can be shown to be transmitted 
in heredity as a whole and independently of other 
qualities or parts.”’? The inheritance im a fertilised 
egg-cell consists of an assemblage of distinct 
ingredients in duplicate, contributed from the 
father and from the mother. If both the germ- 
cells (egg-cell and sperm-cell) bring in a similar 
ingredient when they unite in fertilisation, then 
all the germ-cells of the offspring will have it; 
if neither bring it in, then none of the germ-cells 
of the offspring will have it. Two blue-eyed 
parents (without pigment in the front of the 
iris) do not have dark-eyed children. If the 

1 We must say recent, for although Mendel died two years after 
Darwin and published his great discovery in 1865, his work was lost 
sight of till 1900, when Correns, Tschermak, and De Vries were 
independently led to a rediscovery of Mendel’s law and to a dis- 


covery of his buried memoirs. 
2 W. E. Castle, in “ Fifty Years of Darwinism” (1909), p. 146. 


136 DARWINISM AND HUMAN LIFE 


ingredient come in from one side and not from 
the other, then, on an average, in half the resulting 
germ-cells it will be present, and from half it 
will be absent. “‘ This last phenomenon, which 
is called segregation, constitutes the essence of 
Mendel’s discovery.”! ‘In this,’ Mr. Punnett 
says, “les the explanation of the facts that 
hybrids mated together produce a definite pro- 
portion of the pure forms, which subsequently 
breed true without ever giving a hint of their 
mixed ancestry.” 

Metuops oF Stupyine Herepiry.—In studying 
a difficult problem, such as the weather, there 
are three possible lines of attack: we may make 
minute researches, eg. on the role of dust in 
forming fog; we may make experiments, eg. on 
the change of a cloud into rain, or on the effect 
of tree-planting on climate; or we may collect 
a multitude of observations of a statistical char- 
acter, e.g. as to the rainfall in different localities 
and at different times of year. These are three 
sound methods, which have been worked with 
success. They are complementary, not opposed. 

Similarly, we may attack the problems of 
heredity by the microscopical study of the germ- 
cells in which life is continued from gencration 
to generation, by breeding experiments, and by 
the statistical study of the measurable characters 
of successive generations.? These three different 
methods of attacking the problems of heredity 

1 W. Bateson, “ The Methods and Scope of Genetics ”’ (Cambridge, 
1908), p. 15. 

2 It is of interest to note that Sir Francis Galton, who may be 
taken as the representative of the statistical study, and Gregor 


Mendel, who was the pioneer of the experimental study, were born 
in the same year (1822), 


FACTS OF INHERITANCE 137 


seem to be equally valid, and though the generalisa- 
tions reached along the different lines do not at 
present cohere in a harmonious body of doctrine, 
there is no reason to doubt that this will gradually 
develop. Let us illustrate some of the results 
attained along the three lines. 

MICROSCOPICAL STUDY OF THE GERM-CELLS.— 
Most plants and animals are built up of cells 
and start in life as fertilised egg-cells, and it 
was in a fertilised egg-cell that our own natural 
inheritance consisted. A few exceptions may be 
made—e.g. for bananas, which have no _ longer 
any seeds; for potatoes, which are multiplied by 
cutting; for the drone-bees and summer green- 
flies, which have mothers but no fathers; and 
for the simple, single-celled organisms which are 
themselves comparable to eggs and sperms; but 
the exceptions are trivial compared with the 
vast majority of living creatures of which it is 
certain that each individual life begins as a ferti- 
lised egg-cell—the result of the intimate and 
orderly union of a spermatozoon and an ovum. 

We get a very misleading idea of the ovum, or 
egg-cell, when we think, as we always do at first, 
of birds’ eggs. For in these familiar objects the 
true egg-cell has been dilated by an enormous 
quantity of nutritive yolk, on the top of which 
a minute drop of nucleated living matter lies 
like an inverted watch-glass. Most ova are very 
minute cells, often invisible to the naked eye. 
The spermatozoon, or male element, which fertilises 
the egg, is smaller still; it 1s often only yoo/555 th 
of the ovum’s size. In a way that we cannot 
picture each of the germ-cells (or gametes) carries a 
complete set of hereditary characters, All theory 





138 DARWINISM AND HUMAN LIFE 


apart, it is by the minute germ-cells that the 
secret of life and the character of each kind of 
living creature are sustained from generation to 
generation. Within every cell in the body of an 
organism there is usually a nucleus, and within the 
nucleus a number—a definite number—of readily 
stainable rods, or loops, or grains called chromo- 
somes. livery creature: has a definite number ; 
thus, there are thirty-two or forty-eight in white 
men, twenty-two in the negro, twenty-four in mouse 
and in lily, twelve in the grasshopper, and two in 
a species of threadworm. ‘There is no doubt that 
these stainable bodies, or chromosomes (including 
less visible bodies associated with them), are very 
important. There are many facts pointing to the 
conclusion that they are bearers (not perhaps the 
exclusive bearers) of specifically different materials 
which, in appropriate conditions, will develop into 
particular heritable qualities. One of the leaders 
of experimental zoology, Dr. Przibram, sums up 
a number of remarkable investigations when he 
says: “Substances or parts can be actually 
demonstrated in the ovum, the removal of which 
conditions the absence of definite organs or parts in 
the embryo.” Now, while the immature germ-cells 
have the same number of chromosomes as the 
cells of the body have, the mature germ-cells have 
half the normal number. If 8 be the normal 
number, the ripe ovum has 4, and the fully formed 
spermatozoon has 4, so that when the ovum is 
fertilised the normal number is restored. In a 
remarkable way, by a kind of cell-division which 
occurs only in the maturing germ-cells, the number 
of chromosomes is always reduced by a half— 
except, indeed, in certain cases of parthenogenesis. 


PLATE VIII 








© 








o—— oc. 














lee Ce 
eee Ge 
SP 


GERM-CELLS. 


1. An ovum or egg-cell (OV) with four chromosomes (drawn curved) in its nucleus. 

SP. A spermatozoon or sperm-cell, with four chromosomes CHR (drawn straight) 
in its nucleus. OC. the centrosome, which plays a part in the division of the fertilised 
ovum, 

2. The ovum has given off the first polar body (1 P.B.) which involves—by a meiotic 
division—a reduction of the chromosomes to half the normal number—in this case two. 
Thereafter the nucleus of the ovum has again divided, giving off, by an ordinary or 
equation division, the second polar body (2 P.B.). The reduced nucleus of the ovum 
(F.PN.) is called the female pronucleus. 

3. Fertilisation of the Egg. The female pronucleus (F.PN.) with two chromosomes 
and the male pronucleus (M.PN) also with two chromosomes. ‘The male pronucleus 
is derived from the head of the spermatozoon which has entered the egg. O. the cen- 
trosome, introduced by the spermatozoon. It has divided into two, and each is the 
centre of a system of fine threads. 

4. The egg has divided into two cleavage cells or blastomeres. In each daughter- 
nucleus (DN) the chromosomes are half maternal (drawn curved) and half paternal 
(drawn straight). 

The other figure illustrates the idea of the continuity of the germ-plasm. The broken 
vertical line to the left represents a succession of ova or germ-cells (G.C) from which 
** bodies ’’ (B) are produced, 

The other part of the figure indicates a sequence of bodies (B), the fertilised ova (F.O) 
from which they are produced, the germ-cell lineage (G.C,L), Spermatozoa are repre- 
sented fertilising the ova, 


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FACTS OF INHERITANCE 139 


In this reduction, which means in the case of the 
egg the absolute rejection of half of the chromo- 
somes (which are carried off by the first polar 
body and come to nothing), we see an opportunity 
for permutations and combinations among the 
items of the inheritance, e.g. for the dropping out 
of a character altogether. 

Not less important is the visibly demonstrable 
fact that sperm and ovum contribute the same 
number of chromosomes (except in certain cases 
where half of the spermatozoa have an extra 
chromosome), and that, when the fertilised egg- 
cell divides, each daughter-cell receives the normal 
number of chromosomes, half of maternal origin 
and half of paternal origin. This has been followed 
for several divisions, so that, if the chromosomes 
are inheritance-bearers, we have ocular demonstra- 
tion of the truth of the prophetic statement which 
Huxley made in 1878: “It is conceivable, and 
indeed probable, that every part of the adult 
contains molecules derived both from the male 
and from the female parent; and that, regarded 
as a mass of molecules, the entire organism may 
. be compared to a web of which the warp is 
derived from the female and the woof from the 
male.” 

StaTisTicAL Stupy: f[r1m. ReEGREssion.— 
Darwin’s illustrious cousin, Sir Francis Galton, 
was the pioneer in the statistical study of inherit- 
ance. He convinced biologists of the value of 
collecting statistics as to the resemblances and 
differences in successive generations, e.g. as regards 
stature, colour of eyes, and intellectual ability, and 
he reached several general inductions which 
express the inherent orderliness obtaining even 


140 DARWINISM AND HUMAN LIFE 


in a domain where occurrences seem as capricious 
as those of weather. 

It has often been remarked that the children 
of extraordinarily gifted parents are sometimes 
very ordinary individuals, and that the children 
of under-average parents sometimes turn out 
surprisingly well, both physically and mentally. 
Kvery one who has looked into the facts of in- 
heritance in greater detail, and has compared the 
average of qualities in successive generations, 
has noticed, in a general way, that there is a 
tendency to sustain the same average level from 
generation to generation. HKven the older in- 
quirers, like Lucas, called attention to the fact 
that extraordinary qualities in families tend to 
wane away, as if there were some mysterious 
succession-tax levied on marked deviations from 
the average, whether in the way of excellence or 
of defect. But we owe to Galton’s careful statisti- 
cal work the generalisation known as the Law of 
Filial Regression, which has replaced a vague 
impression by a definite formula. He has defined 
and measured the tendency towards mediocrity, 
the tendency to approximate to the mean, or 
average, of the stock. We must notice, at the 
outset, that this Filial Regression has nothing to 
do with reversion or with degeneration, that it 
works upwards as well as downwards, forwards 
as well as backwards. 

The data which Galton utilised were chiefly the 
records of family faculties, obtained from about 
one hundred and fifty families, and dealing especi- 
ally with stature, eye-colour, temper, artistic 
faculty, and some forms of disease. These were 
supplemented by measurements at Galton’s anthro- 


FACTS OF INHERITANCE 141 


pometric laboratory, and by observations on 
sweet-peas, and to some extent on moths. 

Most trustworthy, however, were the data pro- 
cured in regard to stature, which, as Galton points 
out, is a quality with many advantages as a subject 
of investigation. It is nearly constant during 
mature life, it 1s readily and frequently measured 
with accuracy, and it does not seem to be of appre- 
ciable moment in sexual selection. Its variability, 
though small, is normal; that is to say, it is ex- 
pressible in the normal curve of the frequency of 
error. 

As the subject is by no means easy to those 
unaccustomed to statistical inquiry, and as we 
cannot, within our limits, explain the methods, 
it may be most profitable to give a few illustrative 
quotations from Galton’s “ Natural Inheritance ”’ 
(1889). 

“Tf the word ‘ peculiarity ’ be used to signify 
the difference between the amount of any faculty 
possessed by a man and the average of that 
possessed by the population at large, then the law 
of regression may be described as follows. Hach 
peculiarity in a man is shared by his kinsmen, 
but on the average in a less degree. It 1s reduced 
to a definite fraction of its amount, quite inde- 
pendently of what its amount might be. The 
fraction differs in different orders of kinship, 
becoming smaller as they are more remote” 
(p. 194). 

‘“ However paradoxical it may appear at first 
sight, 1t is theoretically a necessary fact, and one 
that is clearly confirmed by observation, that the 
stature of the adult offspring must on the whole be 
more mediocre than the stature of their parents; 


142 DARWINISM AND HUMAN LIFE 


that is to say, more near to the mean or mid of the 
general population ” (p. 95). 

“The law of regression tells heavily against the 
full hereditary transmission of any gift. Only a 
few out of many children would be likely to differ 
from mediocrity so widely as their mid-parents,} 
and still fewer would differ as widely as the more 
exceptional of the two parents. The more bounti- 
fully a parent is gifted by nature, the more rare 
will be his good fortune if he begets a son who is as 
richly endowed as himself, and still more so if he 
has a son who is endowed yet more largely. But 
the law is even-handed; it levies an equal succes- 
sion-tax on the transmission of badness as of 
goodness. If it discourages the extravagant hopes 
of a gifted parent that his children will inherit all 
his powers, it no less discountenances extravagant 
fears that they will inherit all his weakness and 
disease ”’ (p. 106). 

“It must be clearly understood that there is 
nothing in these statements to invalidate the 
general doctrine that the children of a gifted pair 
are much more likely to be gifted than the children 
of a mediocre pair. They merely express the fact 
that the ablest of all the children of a few gifted 
pairs is not likely to be as gifted as the ablest of all 
the children of a very great many mediocre pairs ” 
(p. 106). 

Nor must the fact of regression be supposed 
to affect the general value of a good stock or the 
general disadvantage of a bad one. Two gifted 
members of a poor stock may be personally equiva- 


1 The mid-parent is a statistical fiction, with a stature half that 
of the two parents when allowance is made for the average difference 
of stature in the two sexes. 


FACTS OF INHERITANCE 143 


lent to two ordinary members of a good stock, 
but “the children of the former will tend to re- 
gress ; those of the latter will not” (p. 198). 

Let us give a concrete illustration from Prof. Karl 
Pearson’s ‘‘Grammar of Science”’ (1900, p. 454): 
“ Fathers of a given height have not sons all of a 
given height, but an array of sons of a mean height 
different from that of the father and nearer to the 
mean height of sons in general. Thus, take fathers 
of stature 72 inches, the mean height of their sons 
is 70°8 in., or we have a regression towards the mean 
of the general population. On the other hand, 
fathers with a mean height of 66 in. give a 
group of sons of mean height 68°3 in., or they have 
progressed towards the mean of the general popula- 
tion of sons. The father with a great excess of the 
character contributes sons with an excess, but a 
less excess of it; the father with a great defect 
of the character contributes sons with a defect, 
but less defect of it. The general result is a sensible 
stability of type and variation from generation to 
generation.” 

There seems no reason to doubt the general 
occurrence of regression towards mediocrity, though 
the law requires modification in regard to charac- 
ters which are subject to keen selection, either 
natural or sexual, and though it does not apply to 
sharply defined “unit characters’? which do not 
blend. : 

Gatton’s Law or ANCESTRAL INHERITANCE.— 
It is necessary, however, to ask what this statis- 
tically established fact of filial regression really 
means biologically. 

In all ordinary cases of reproduction the off- 
spring has a strictly dual or bi-parental inheritance. 


144. DARWINISM AND HUMAN LIFE 


Whatever the inheritance may be in its expression— 
whether it show a blend or take after one side of the 
house—it is made up, to begin with, of approxi- 
mately equal contributions from the two parents. 
We say “ approximately,” for it often happens that 
the germinal “ factor,” ‘‘ determinant,”’ or “ gene,” 
which brings about a particular character, is 
present in one parent only. But the contribution 
from the father is made up of contributions from his 
two parents, and the contribution from the mother 
is made up of contributions from her two parents. 
And so on backwards. Thus we reach the idea, to 
be corrected in cases where Mendelian inheritance 
has been proved for particular characters, that an 
individual inheritanceisa mosaic of ancestral contri- 
butions. Corroborations are familiar—e.g. in the re- 
expression of the peculiarities of a remote ancestor. 

But we owe to Galton’s careful statistical work, 
as to stature and other qualities in man, and as 
to coat-colour in Basset hounds, a generalisation 
which formulates the share which the various 
ancestors have, on an average, in the inheritance 
of any individual organism. This Law of Ancestral 
Inheritance is as follows: “The two parents 
between them contribute, on the average, one-half 
of each inherited faculty, each of them contributing 
one-quarter of it. The four grandparents con- 
tribute between them one-quarter, or each of them 
one-sixteenth ; and so on, the sum of the series 
g+it+i+ A+..., being equal to 1, as 
it should be. It is a property of this infinite 
series that each term is equal to the sum of all 
those that follow: thuuydEI=4+2+,+..., 
A4=3+ A+ ..., and so on. The prepo- 
tencies or subpotencies of particular ancestors, in 


FACTS OF INHERITANCE 145 


any given pedigree, are eliminated by a law that 
deals only with average contributions, and the 
varying prepotencies of sex in respect to different 
qualities are also presumably eliminated.” Thus 
an inheritance is not merely dual, but through the 
parents it is multiple, and the average contribu- 
tions made by grand-parents, great-grandparents, 
etc., are definite, and diminish in a precise ratio 
according to the remoteness of the ancestors. 

EXPERIMENTAL Stupy.—Perhaps we may most 
profitably illustrate the experimental study of 
heredity by asking what the possible results are 
of pairing two hypothetical organisms. Although 
prediction as to the result of any individual pairing 
is apt to be falsified (except in clear cases of 
Mendelian inheritance), there are some well- 
known alternatives of expectation. 

(1) Pairing of Similar Pure-bred Forms.—Let 
us begin with the offspring of similar pure-bred 
organisms. When similar forms are bred together 
for several generations a certain uniformity of type 
is likely to result. If by selection the most similar 
are mated together, while the least similar are 
persistently removed from the stock, and if there 
is also some measure of inbreeding, then there is 
likely to be more or less constant uniformity of 
type. These “ pure-bred” organisms produce 
others like themselves, and we suppose this to mean 
that the hereditary items in the ovum have not 
only their counterpart, but their equivalent, among 
the hereditary items in the spermatozoon. This, 
then, is one of the modes of inheritance—that the off- 
spring closely resemble the parents and one another. 
The variability is restricted within a small range. 

(2) Blending.—Passing from the mating of 


10 


146 DARWINISM AND HUMAN LIFE 


similar pure-bred organisms to other cases, we note, 
as an occasional occurrence, that the offspring 1s a 
combination of the paternal and maternal charac- 
teristics in such a thoroughgoing way that the 
result may be described as an intimate blend. Ina 
cross between the long-eared lop-rabbit and a short- 
eared breed, Castle found that forms with ears of 
intermediate length are produced, and that these 
intermediates breed true. ‘The colour of the skin 
in mankind seems to blend when white and black 
races are crossed. Blending is well illustrated by 
some cockatoo hybrids and in many plants. 

(3) Parteculate Inheritance.—The offspring often 
show what may be called a coarse-grained or 
non-blended combination of the paternal and 
maternal characteristics, the former appearing in 
one part of the body, the latter in another part, as 
when a light-coloured horse and a dark-coloured 
mare have a piebald foal, or when a sheep-dog has 
an eye like its father on one side and an eye like its 
mother on the other side. This is often described 
as particulate inheritance. 

(4) Haclusive Inherttance.—lt often happens 
that the offspring takes wholly after one of its 
parents, or wholly as regards particular organs, 
and extreme forms of this are spoken of as exclusive 
inheritance. The inheritance of eye-colour in 
mankind belongs to this type. Although the 
inheritance is dual, it seems as if only one set of 
the heritable characters found expression—at least 
as regards particular organs. The more pure-bred 
parent is the more likely to be prepotent in the 
inheritance. This exclusive inheritance may be 
the first step in a clear Mendelian case, which we 
shall consider later. 


FACTS OF INHERITANCE 147 


(5) Reversion—Another mode of inheritance 
—known as Reversion—is seen when the offspring 
exhibits features which were not expressed in its 
immediate ancestry, but were characteristic of 
more remote ancestry, as when crossing different 
races of pigeons, which have been breeding true, 
results in the production of the ancestral rock- 
dove type. Professor Cossar Ewart crossed an 
“Owl” with an “ Archangel” and obtained a 
hybrid more like the former than the latter. He 
crossed this with a prepotent white fantail and 
obtained two pigeons closely resembling the wild 
rock-dove type. Darwin laid stress on such 
reversionary Blue Rocks which occur when widely 
differing breeds are crossed and the hybrids are 
bred together, but some recent experiments, e.g. 
those of Staples-Browne, suggest that there may 
be a Mendelian interpretation even of Darwin’s 
classic cases of reversion. The case of rabbits is 
very suggestive. When rabbits of different colours 
are turned loose and breed together, their descend- 
ants tend to be eventually all grey. Darwin 
regarded this as a reversion, and it may still be 
described as reversionary; but it is not due to 
the reassertion of long latent grey colouring. The 
return to grey is due, as the Mendelian experiments 
show, to the recombination of at least eight 
colour-ingredients that go to the make-up of 
wild greyness. Man has sifted out all the various 
colours from the complex coloration of the wild 
stock, and when the long-separated items are 
brought together again by unrestricted inter- 
breeding there is, naturally enough, a reconstruction 
of the original grey colour. 

(6) New Departures.—Just as we began by 


148 DARWINISM AND HUMAN LIFE 


noting that the ofispring of carefully pure-bred 
types might be almost replicas of the parents, 
so we must notice the opposite extreme, where 
the offspring represent something quite new—a 
novel position of organic equilibrium—a “ freak,” 
or “sport,” or “ mutation,’ or “ discontinuous 
variation.”” That these new departures have some- 
times formed the beginning of a new domesticated 
breed or cultivated variety is well known; and 
it is possible that species in nature may sometimes 
have arisen in a similar way. 

(7) Mendelian Inheritance—In typical cases 
of Mendelian inheritance we have to do with the 
pairing of two pure-bred types which differ from 
one another in respect of one or more unit char- 
acters, which may be obvious qualities, such as 
colour and markings, or more subtle qualities, 
such as the loaf-producing “ strength ”’ of wheat, 
its susceptibility or immunity in respect to rust, 
the broodiness or non-broodiness of poultry, 
the horned or hornless state of the head in 
cattle. 

The result of the crossing is that the “ hybrid ” 
progeny all resemble one parent in respect of 
the contrasted characters. There are no inter- 
mediates, for Mendelian characters do not blend. 
The offspring of grey and white mice are all grey; 
the offspring of giant and dwarf peas are all tall ; 
and so on. It is usual to speak of the character 
that persists and is expressed as the dominant 
character, while that which remains unexpressed 
or latent is called recessive. 

But when the “hybrids” are inbred, the next 
generation shows a reappearance of the original 
parental types both dominant and recessive— 


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FACTS OF INHERITANCE 149 


both breeding true—and a number of forms, 
usually lake pure dominants, which, when inbred, 
again produce “pure dominants,” “pure 
recessives,” and “‘impure dominants ” like them- 
selves. In typical cases, where attention is paid 
to one pair of contrasted characters, the proportions 
of the “hybrids” always approximate to the 
formula—1l pure dominant: 2 impure dominants : 
1 pure recessive. 
This may be expressed in a simple schema : 


Dr ocr kh arden cit tele. Parents 
| | | 
D(R) otalte tou ete Hybrids. F! 
x 
D(R) 


| 
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Extracted Impure Extracted 
Pure Dominants Pure 
Dominants pep Recessives 


yg PO a | 
DD 1DD+2D(R)+RR RR _ 3rd Generation F® 


Mendel explained his results by the ingeniously 
simple hypothesis of segregation. He supposed 
that the germ-cells of the hybrids segregated into 
two contingents, one half bearing the dominant 
character and one half bearing the recessive 
character. If fertilisations follow the laws of 
chance the second generation should theoretically 
show the proportions which actually occur. When 
there are two pairs of contrasted characters— 
for instance, when a tall yellow-seeded (Dd) pea 
is crossed with a dwarf green-seeded one (Rr)— 
the offspring are tall yellows (Dd), combining the 


150 DARWINISM AND HUMAN LIFE 


two dominant features; and when these are self- 
fertilised (which is equivalent to inbreeding), 
out of 16 offspring there are 9 tall yellows (Dd), 
3 tall greens (Dr), 3 dwarf yellows (Rd), and one 
dwarf green (Rr). When a rabbit of the wild 
grey colour is crossed with an albino, the offspring 
are all grey, and these, if bred together, give in 
certain cases 9 greys, 3 blacks, and 4 albinos, 
which is a slight modification of the ordinary 
9:3:3, I ratio due to the impossibility of dis- 
tinguishing, by external appearance, between two 
different kinds of albino. 

Unit Coaracters.—We do not at present know 
with certainty how many qualities and parts can 
be called “unit characters” in the Mendelian 
sense. The only criterion is the experimental one: 
can the character be lost, as a whole, in cross- 
breeding? Prof. W. HE. Castle’ gives an illustra- 
tion: “If we cross a black guinea-pig with one 
which lacks black—say a brown one—we obtain 
only black offspring ; but these bred enter se produce 
black offspring and brown ones, in the proportion 
three black to one brown. We thus learn that 
black is a unit character. It was contributed by 
one parent to the cross, but not by the other, and 
transmitted by the cross-bred individual to half 
its offspring, but not to the other half. This is 
Mendel’s explanation of the 3:1 ratio, now 
familiar to every biologist. 

“ But if we cross the same black parent in the 
foregoing case, not with a brown individual, but 
with a white one or with a yellow one, we may 
obtain, not black offspring, but wild-coloured 


1 «« The Behaviour of Unit Characters in Heredity,” in “ Fifty 
Years of Darwinism ’’ (1909), p. 148. 


FACTS OF INHERITANCE 151 


‘agouti’ ones, which bred «nter se will produce 
agouti, black, white (or else yellow) young, with 
perhaps those of other new classes in addition. 
Such a result as this puzzled Darwin, and would 
naturally puzzle any one; but in the light of 
Mendel’s law becomes capable of ready explanation. 
The production of black pigment is a process in 
which more than one unit character is concerned, 
the production of a grey coat involves more 
units still. ... What was unknown to Mendel 
has been made clear since 1900: that in many 
cases two or more independent unit characters 
must be present to produce a single visible 
effect.”’ a 

THe Case or ANDALUSIAN Fow.us.—The pheno- 
mena of Mendelian inheritance are well illustrated 
in the case of the Blue Andalusian fowl. We quote 
Mr. Punnett’s account’: “The Andalusian has long 
been known to possess an inconvenient peculiarity : 
it will not breed true. It always throws‘ wasters ’ 
of two sorts: blacks, and whites marked with some 
black splashes. There are, therefore, three kinds 
of Andalusians, and consequently six possible 
types of mating among these three varieties. With 
regard to the results of these types of mating, 
careful experiment has brought out the following 
facts : 


Blue x Blue gives Blacks, Blues, and Whites, in the ratiol:2:1. 
Blue x Black ,, Blacks and Blues in equal numbers. 

Blue x White,, Blues and Whites in equal numbers. 
Black x Black ,, Blacks only. 

White x White ,, Whites only. 

Black x White ,, Blues only. 


1 «“Mendelism in Relation to Disease,” ‘Proc. Roy. Soc. 
Medicine’’ (March 1908). 


152 DARWINISM AND HUMAN LIFE 


“We are dealing here with a case in which every 
possible form of mating has been carried out, and 
some of the results, at first sight, seem paradoxical. 
Thus, for instance, the blacks always breed true, 
whatever their ancestry may have been; and the 
same holds good for the whites. The white that 
is produced by two blues, themselves the product 
of mating blue with blue over many generations, 
breeds as true to whiteness as the white of pure 
white ancestry. A black is pure for blackness and 
a white is pure for whiteness, whatever the ancestry 
of the bird may have been. Again, it seems at first 
sight incongruous that the mating of black with 
white should give just twice as many blues as two 
blues mated together. 

“We are dealing with an alternative pair of 
characters, blackness and whiteness. Every germ- 
cell, or gamete, whether ovum or spermatozoon, 
bears a representative of this pair. But it can 
bear only one representative, viz. evther blackness 
or whiteness.- Hence for this pair of characters 
there are two, and only two, types of gamete: 
‘black’ gametes and ‘white’ gametes. When 
a black gamete meets a black the result is a black 
bird; when a white meets a white the result is a 
white bird; but when a white meets a black the 
resulting zygote’ contains the representatives or 
factors for both blackness and whiteness, and 
develops into a blue bird. Now we must suppose 
that the gametic representative of a character, 
the factor, is an unsplittable entity so far as 
inheritance is concerned. The zygote, being 

1 Gamete is the technical term for a germ-cell, either egg-cell 


or sperm-cell; zygote is the technical term for the egg-cell after it 
has been fertilised by the sperm-cell. 


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FACTS OF INHERITANCE 153 


formed by two gametes, must contain two factors. 
It is a double structure, and, when it comes to 
form gametes, these single structures are produced 
by the separation of the two factors present in 
any zygotic cell. The factors representing the 
characters are said to segregate from one another in 
the process. In a zygote produced by the union 
of similar gametes, the segregation 1s between like 
factors, and all the gametes produced are alike. 
But a zygote which has been formed by two 
dissimilar gametes, each bearing one of the factors 
corresponding to a pair of characters, must, on 
forming gametes, give rise to gametes of two sorts, 
and must give rise to them in equal numbers. 
On this simple hypothesis is afforded a ready 
explanation of the various experimental facts 
given above. 

“A blue hen is producing equal numbers of 
‘black’ and ‘white’ eggs—let us say 2n of 
each. To fertilise these eggs are brought large 
numbers of spermatozoa of the two sorts, black and 
white, in equal numbers. Every black egg, then, 
has an equal chance of being fertilised by a black 
or a white spermatozoon. In the former case it 
will form a black, and in the latter a blue, bird. 
From our 2n black eggs we shall obtain n black, 
and » blue birds; that is to say, the mating of 
blue with blue must, on the assumption of the 
purity of the gametes, give black, blue, and white 
Wistherrationl sac lanes 

Wattzinc Micr.—Let us take another illustra- 
tion relating to the quaint Japanese waltzing 
mice, which waltz round and round in circles and 
have only one semicircular canal of the ear well 
developed. When waltzing mice are crossed with 


154 DARWINISM AND HUMAN LIFE 


normal mice all the progeny are normal. The 
waltzing habit is recessive, the normal is dominant. 
When the hybrids are inbred the resulting genera- 
tion consists of normal mice and waltzing mice in 
the proportion of three dominants to one recessive. 
The recessives of this generation, when inbred, 
yield only recessives, for as many generations as 
one likes to breed them. The dominants are 
found to be of two kinds: one-third of them— 
called pure dominants—when inbred yield only 
dominants; the other two-thirds—called ampure 
dominants—yield dominants and recessives in the 
old proportions of 3: I. 

It is supposed that the hybrids have germ-cells 
of two kinds, one half bearing the waltzing charac- 
ter, the other the normal character. Hach germ-cell 
is “pure” as regards this character. There are 
twice as many chances of the unlike combination 
occurring—that is, of normal and waltzing—as of 
the like combination occurring—that is, of normal 
méeting normal, or waltzing waltzing. In other 
words, the percentage of individuals in the three 
groups will be what it is: 25 pure normal, 50 
impure normal, and 25 pure waltzing. 

OccuRRENCE OF MENDELIAN INHERITANCE.— 
Mendelian phenomena are known in rats, mice, 
rabbits, guinea-pigs, poultry, canaries, snails, silk- 
worms, and some other animals; in peas, beans, 
stocks, wheat, barley, maize, and some other 
plants. The characters which illustrate it are 
such as size, colour, markings, crests, horns, hairi- 
ness, peculiar features such as the waltzing habit 
in mice, and elusive properties, such as broodiness 
in hens, time of ripening and immunity m wheat. 

It is doubtful how far Mendelian phenomena 


FACTS OF INHERITANCE 155 


occur in man. Human eyes may be arranged in 
two groups: (a) those with brown pigment on the 
outer as well as on the inner surface of the iris 
(usually browns and greens) ; and (6) those without 
such brown pigment on the outer side, but with 
some pigment on the mner side (blues and greys), 
It appears, from the researches of Hurst and of 
Prof. and Mrs. Davenport, that the first type is 
dominant and the second recessive. Hurst also 
gives some evidence that “ fiery red ” hair behaves 
as a recessive to brown, and that the musical sense 
is recessive to the non-musical. The clearest case, 
as yet, is that peculiar condition of the hands and 
feet known as brachydactyly, which Farabee and 
Drinkwater have found to be dominant to the 
normal condition. Of great interest also is Mr. 
Nettleship’s account of the descendants of one 
Jean Nougaret (born 1637) who was afflicted with 
night blindness—a condition apparently due to loss 
of the visual purple. There are records of over 
2,000 individuals; and the night blindness is 
dominant over the normal. During two and a half 
centuries no normal member of the family who 
has married another normal, whether related or 
not, has ever transmitted the disease. 
PRAcTICAL IMPORTANCE OF MENDELISM.—The 
work of the Mendelian school of experimenters 
since 1900 is full of achievement and promise, and 
no naturalist can help envying those who have been 
able to share in it, all the more that their dis- 
coveries are full of practical as well as theoretical 
import. Prof. Bateson writes: “If we want to 
raise mangels that will not run to seed, or to breed 
a cow that will give more milk in less time, or milk 
with more butter and less water, we can turn to 


156 DARWINISM AND HUMAN LIFE 


genetics with every hope that something can be 
done in these laudable directions. But here I 
would plead what I cannot but regard as a higher 
usefulness in our work. Genetic inquiry aims at 
providing knowledge that may bring, and I think 
will bring, certainty into a region of human affairs 
and concepts which might have been supposed re- 
served for ages to be the domain of the visionary.” 
He alludes to lability to particular disease, addic- 
tion to a particular vice, and so on, and says: “ As 
regards the more tangible of these physical and 
mental characteristics there can be little doubt 
that, before many years have passed, the laws of 
their transmission will be expressible in simple 
formule.” * 

Mucu Proacress, BUT GREAT UNCERTAINTY.— 
Especially through the work of the Mendelians 
great strides have been made in the last ten years 
in our knowledge of the laws of inheritance. By 
breeding two pairs of rabbits which, to the ordinary 
eye, seem identical, an experimenter like Mr. Hurst 
acquires a knowledge of their inherent germinal 
qualities (or gametic constitution), and he can 
successfully predict the difference between the 
results of mating the two pairs. The statisticians 
can predict average results in 1,000 offspring ; the 
Mendelian breeder can predict the distribution of 
certain characters in a litter. In spite of this 
progress, and partly because of it, we are confronted 
with an array of unanswered questions concerning 
this most fascinating of problems. In what cases 
are the facts of inheritance clearly Mendelian, 
and how do these cases differ from others that 
seem as clearly non-Mendelian? Is it the case 

1 W. Bateson, ‘‘ The Methods and Scope of Genetics ”’ (1908). 


FACTS OF INHERITANCE 157 


that particular ancestral qualities may be latent 
for more than two generations, and then re-assert 
themselves as reversions? What adjustment of 
statement, if any, will bring Galton’s Law (a 
statistical conclusion) and Mendel’s Law (an 
experimental conclusion) into harmony ? What is 
the nature of the character which we call “ male- 
ness’ or “femaleness,” and is there any law 
which will formulate its distribution in the progeny 
ofa pair? These are some of the urgent questions 
towards the answering of which facts are accumu- 
lating every month. 

THE TRANSMISSION OF ACQUIRED CHARACTERS.— 
Let us turn, however, for a little to the long-drawn- 
out controversy as to the possible transmission of 
“acquired characters,” or somatic modifications. 
It may be said that the disputants are now agreed 
as to the precise point at issue, and perhaps it 
may also be said that neither the yeas nor the nays 
ring out so confidently as they did some years ago. 
Let us state the case. Members of the same species 
often differ from one another, and these differences 
can be measured and registered under the title of 
** observed differences,’’ which commits one to no 
theory. Many of these differences depend on age 
and sex, and these can be readily recognised and 
allowed for. Others depend on peculiarities of 
“ nurture,’ in the wide sense; that is, they are 
the direct results of peculiarities in surrounding 
influences or in function. Such changes in plant 
or animal are impressed from without, they are 
“exogenous ”’ in origin, they are acquired not 
inborn, and they are technically called ‘‘ somatic 
modifications,” or ‘‘ acquired characters.” They 
may be defined as structural changes in the body of 


158 DARWINISM AND HUMAN LIFE 


an individual directly induced by changes in function 
or in environment, which transcend the limit of 
organic elasticity and thus persist after the inducing 
conditions have ceased to operate. Thus fattening 
and sunburning are modifications, though the 
predisposition to them may be inborn; the forma- 
tion of a callosity as the result of pressure and 
the reduction of a muscle by prolonged disuse are 
modifications, though it does not, of course, follow 
that callosities and reduced muscles may not come 
aboutin a quite different way, namely, by a germinal 
variation. Now, when. we subtract from the total 
of observed differences between members of the 
same species all that can be described as modzifica- 
tions, we find a large remainder which we must 
define off as mmborn or germinal variations. We 
cannot causally relate them to any peculiarities 
in the organism’s habits or surroundings, they are 
often distinct at birth or hinted at before birth, 
they are rarely alike even among forms whose 
conditions of life seem absolutely uniform. They 
are endogenous, not exogenous in origin; they are 
results of changes in the germinal material; they 
are born, not made ; and they are more or less trans- 
missible, though they are not by any means always 
transmitted.| They form—at least some of them 
form—the raw material of organic evolution, 
whereas modifications, as defined, are probably not 
of direct importance in evolution, since we have no 
secure evidence that they are ever transmitted as 
such, or in any representative degree. 


1 Continuous variations or “ fluctuations ” are sometimes trans- 
mitted and in varying degrees; transilient variations or mutations 
have the capability of being transmitted intact to a certain pro- 
portion of the progeny, while reversion may occur in others. 


FACTS OF INHERITANCE 159 


There is no doubt that modifications are very 
common, that they are of much individual import- 
ance, that they may have an indirect influence 
through the body on the offspring (especially in 
the case of mammalian mothers), that they may 
have an indirect importance in evolution in several 
ways, but the precise point at issue is this: Does 
a structural change in a part of the body, induced by 
use or disuse, or by change in surroundings and 
nurture generally, ever influence the germ-plasm in 
the reproductive organs in such a specific or re- 
presentative way that the offspring will thereby 
exhibit the same modification that the parent ac- 
quired, or even a tendency towards %? We do not 
know of any clear case which would at present 
warrant the assertion that a somatic modification 
is ever transmitted from parent to ofispring. 

In regard to this important question, let us try to 
clear the ground by noting a few of the common 
misunderstandings.* 

I. How can there be progressive evolution if 
acquired characters are not entailed? By the 
accumulation of germinal variations, such as those 
which have separated the higher from the lower 
races of mankind. Yet Herbert Spencer actually 
said, “‘ Hither there has been inheritance of acquired 
characters, or there has been no evolution.” In 
1796 the speed of the English trotter was a mile 
in 2 mins. 37 secs. ; it 1s now a mile in 2 mins. 
10 secs., or less; but that is the result of the 
selection of inborn variations, not of the trans- 
mission of acquired characters. 

I]. Many facts in nature are readily interpretable 


1 See “ Heredity,” by J. Arthur Thomson, (Murray. London 
1908.) 


160 DARWINISM AND HUMAN LIFE 


on the theory that the results of use and disuse and 
of environmental change are, as such, transmissible. 
The black skin may be interpreted as due to the 
sun. The callosities on the knees of the wart-hog 
may be interpreted as due to pressure on the ground. 
The twelve hours’ sleeping and waking of many 
acacias may be interpreted as a functional adap- 
tation which has become hereditary. But the 
interpretations may be erroneous. 

III. Many beg the question by starting with a 
character, like short-sightedness or gout, which 
has not been proved to be a modification. First 
catch your modification. The little toe is said to 
be dwindling in consequence of wearing tight boots ; 
but we are not sure that there is dwindling, and if 
there is, we have no experimental reason for blaming 
the boots. 

IV. The reappearance of a modification in suc- 
cessive generations is often mistaken for trans- 
mission. It may be hammered on to each suc- 
cessive generation. Nigeli put Alpine plants in 
rich garden soil and they became very different, 
and their progeny likewise; but transference to 
poor soil brought back the Alpine characters, which 
showed that the new characters had not taken 
any hereditary grip. 

V. Infection of the offspring by the parent before 
birth has nothing to do with inheritance in the 
true sense. 

VI. Transmission in unicellular organisms is not 
to the point, for, as they have no “ body,” the 
concept of somatic modifications does not apply to 
them. 

VII. Changes in -the germ-cells along with 
changes in the body, where there are deeply 


FACTS OF INHERITANCE 161 


saturating influences such as poisons, are not 
cogent. 

VIII. Modifications may have secondary effects 
on the germ-cells and the offspring, e.g. in the way 
of bad nutrition, but unless the offsprmg show 
peculiarities 7m the same direction as the original 
modifications, we have no data bearing precisely 
on the question at issue. 

A belief in the inheritance of modifications was 
perhaps expressed in the old proverb, “ The fathers 
have eaten sour grapes, and the children’s teeth 
are set on edge ’—a proverb which Ezekiel, with 
such solemnity, said was not any more to be used 
in Israel. Now if “setting on edge” was a 
structural modification, and if the children’s teeth 
were ‘set on edge” as their fathers’ had been 
before them, there would be a presumption in 
favour of the transmission of this acquired char- 
acter, though it would be still necessary to inquire 
carefully whether the children had not been in the 
vineyard too. If, as Romanes said, the children 
were born with wry necks, we should have to deal 
with the inheritance of an indirect result of the 
parents’ vagaries of appetite, and not with any 
direct representation in inheritance of the particu- 
lar modification produced in the paternal dentition. 

IX. Finally, there is no use appealing to data 
from fewer than three generations. Sheep trans- 
ported to a cold country get longer fleece, their 
offspring have still longer fleece; but this is not 
to the point, since the offspring were subjected to 
the modifying influences from birth. We wish 
to know whether the third generation is more 
markedly modified than the second. 

DisEASE.—As a particular case we may take 

1] 


162 DARWINISM AND HUMAN LIFE 


the important question of the transmissibility of 
acquired disease. When the question is carefully 
considered, it seems possible to distinguish be- 
tween (1) abnormal or deranged processes which 
have their roots in germinal peculiarities or de- 
fects (variations), and (2) abnormal or deranged 
processes which have been directly induced 
in the body by acquired modifications, 1.e. as 
the results of unnatural surroundings or habits, 
including the intrusion of parasites. There is 
very little evidence to suggest that this second 
kind of disease is heritable as such, though the 
indirect effects may influence the offspring. When 
we go further and come to understand that pre- 
natal infection is not inheritance, that inheritance 
of a predisposition to a disease is not inheritance 
of the disease, that the general weakening of the 
offspring through disease in the parent is a very 
different matter from the transmission of a specific 
disease, we are almost irresistibly led to the con- 
clusion that in the sense in which the word “ in- 
herited ” is used in biology, there are no inherited 
diseases. What does seem to be inherited, how- 
ever, is a defectiveness or degeneracy of the germ- 
plasm which finds one expression in the parent and 
another in the offspring. 

Facts AND Possipitiries.—The evidence in 
support of the transmission of acquired characters 
is either very anecdotal or very uncritical, and, 
until some cogent cases are forthcoming, the 
thoroughgoing scepticism which Weismann ex- 
pressed many years ago remains justified. 

Besides the unsatisfactory nature of the evidence, 
we have to admit the difficulty of imagining any 
means whereby a modification of a particular 


FACTS OF INHERITANCE 163 


organ of the body can react upon the germ-cells in 
a manner so specific that these can, when they 
develop, reproduce the particular parental modifi- 
cation or any approach to it. Darwin and Spencer 
both faced this difficulty, and tried to meet it; but 
no one now accepts their provisional hypotheses. 
It is true that a mechanism may exist though it 
remains unknown; it is true that important in- 
fluences, mysterious in their nexus, pass from 
reproductive organs to body; but we should not 
have recourse to difficult hypotheses before we 
are sure that there is any need for them. There 
is no doubt that the germ-plasm may be influ- 
enced by the blood, but this is different from 
admitting the transmission of a particular acquired 
character. 

In a well-known case, where the evidence points, 
according to some, to the heritability of an arti- 
ficially induced epileptic condition, it has been 
suggested that the epilepsy produces a toxin which 
passes to the germ-cells so that the offspring are 
epileptically affected. Now if we dared to suppose 
that a deeply saturating modification produces a 
representative chemical substance analogous to a 
toxin, and that this passes to the germ-cells, the 
hereditary reappearance of a modification would 
be more conceivable. 

There are many who think that, sooner or later, 
there must be a return to Darwin’s idea of pan- 
genesis—of specific substances passing from body 
to germ-cells. The study of hormones is a line of 
investigation that is of much interest in this con- 
nection. “Hormones” are specific substances 
produced by cells, and passed into the blood- 
stream to play an important part in stimulating 


164. DARWINISM AND HUMAN LIFE 


or controlling developmental and metabolic pro- 
cesses. Injection of extracts of thyroid has usually 
a beneficial effect in reducing goitre. Injection of 
extracts of foetus has an effect on the mammary 
glands. Injection of testicular extract causes the 
temporary development of a cock’s comb on a hen. 
There are enough of facts of this kind to make us 
chary of dogmatism in regard to the possibility of 
an influence passing from a modification of the 
body to the germ-cells thereof. As Prof. EH. B. 
Wilson says: “ Let us admit freely that such an 
interaction as Darwin assumed may be a real and 
potent factor in heredity, though it gives us no 
hint of its existence in the visible apparatus of 
the cell. In the present defective state of our 
knowledge we may well grant that there may 
be many a thing between germ-cell and body 
that is not yet dreamed of in our biological 
philosophy.””} 

A Striking CasE.—Kammerer’s experiments on 
salamanders afford the most remarkable piece of 
evidence as yet adduced in support of the thesis 
that acquired characters may be transmitted. 

(2) The common yellow and_ black-spotted 
salamander (Salamandra maculosa) is either vivi- 
parous, producing a large number of larve 
25-30 mm. in length with four limbs and short 
gills, or ovo-viviparous, laying large eggs which 
hatch out into similar larvee 23-25 mm. in length. 
After a few months of larval life in the water, 
they undergo metamorphosis into land-salamanders 
45-56 mm. in length. 

(6) The black Alpine Salamander (Salamandra 


1 «The Cell in Relation to Heredity and Evolution,” in “ Fifty 
Years of Darwinism ” (1909), p. 113. 


FACTS OF INHERITANCE 165 


atra) produces at birth two fully formed terrestrial 
young 38-40 mm. in length. 

(c) Kammerer kept S. maculosa in the cold, 
and got it, after a few pregnancies, to produce only 
two young ones, as in S. ara. 

(d) He kept S. atra in a warm place with plenty 
of water, and got it to produce 3-9 aquatic larve, 
thus approaching the condition in S. maculosa. 

(ec) The offspring of the Salamanders thus 
treated (¢ and d), became sexually mature when 
three and a half years old in conditions normal 
to S. maculosa. The offspring of (c) gave birth 
(1) to very advanced larve, 45 mm. long with 
much-reduced gills, metamorphosing several days 
after, or moderately advanced aquatic larve 
40 mm. long, with large gills; or (2) to small 
larvee, 20 mm. long, with rudimentary gills, laid 
on land, and metamorphosing after four weeks 
into salamanders 29 mm. long. Thus there was 
a partial persistence of a modified mode of re- 
production in the absence of the modifying 
conditions. 

(f) The offspring of (d) bore in the water 3-5 
larve, 33-40 mm. or 21-23 mm. in length, light 
in colour, and possessing gills. Thus there was 
an augmentation of the parental modification 
(zd) in conditions which resembled those of the 
original experiment. 

The difficulties in regard to this very interesting 
set of experiments are: (1) they do not deal 
with a structural modification; (2) it 1s possible 
that the experimental conditions acted directly 
on the germ-cells in (c) and (d); (3) there was 
some measure of artificiality in the conditions 
under which the second generation developed, 


166 DARWINISM AND HUMAN LIFE 


which may have disturbed the normal routine of 
reproduction. 

LocicaAL PosITIoN OF rHE QUESTION.—Let us 
notice the logical position of the question. There 
are two possible lines of argument: (a) by experi- 
ment, and (6) by interpretation. (a) As to ez- 
periment, it is plain that hundreds of failures 
to prove the transmission do not demonstrate 
its impossibility. They only show that it is 
not usual. One good case experimentally proved 
would show that the transmission is_ possible. 
The best case we know is Kammerer’s, and it 
does not seem cogent. Perhaps better cases will 
become known. The Lamarckian does not, of 
course, say that every change of conditions will 
produce appreciable hereditary effects in a few 
generations, or that any particular change of 
conditions chosen more or less arbitrarily for 
experimental purposes will produce recognisable 
results in the following generation. But do we 
know of any clear case of even a faint trace of a 
well-defined structural modification being trans- 
mitted ? (b) As to the second method, that of 
the interpretation of facts, 1t cannot be conclusive 
either, since each side has to prove a negative in 
order to establish its case. The Neo-Lamarckians 
have to show that the phenomena they adduce 
as illustrations of modification-inheritance cannot 
be interpreted as the results of selection operating 
on germinal variations. In order to do this to 
the satisfaction of the other side, the Neo-Lamarck- 
lans must prove that the characters in question 
are outside the scope of natural selection, that 
they are non-utilitarian and not correlated with 
any useful characters—a manifestly difficult task. 


FACTS OF INHERITANCE 167 


The Neo-Darwinians, on the other hand, have to 
prove that the phenomena in question cannot 
be the results of modification-inheritance. And 
this 1s, In most cases, impossible. Thus we seem 
to reach a logical dead-lock. What we need are 
more facts. 

CASES WHERE THE Turory OF MOoDIFrICATION- 
INHERITANCE IS INAPPLICABLE.—It 1s true, how- 
ever, that there are certain characters of particular 
organisms in regard to which it may be said with 
some security that they could not have arisen by 
the inheritance of acquired modifications. Thus 
many insects, and the like, have adaptive characters 
in their cuticular structures—knobs for crushing, 
saws suited for cutting, gimlets suited for boring, 
and so on. But these cuticular structures are 
non-cellular, non-living parts of the external 
investment of the body; they are made and 
remade (after moulting) by the underlying, living 
skin. How, then, can they be interpreted in 
terms of modification-inheritance? The matter 
becomes even more difficult when we consider 
cases in which the adaptiveness is in the colour 
or markings of these inert cuticular parts. Weis- 
mann has argued that, since there are some adaptive 
characters which cannot be interpreted in terms 
of modification-inheritance, this hypothetical factor 
need not be assumed in attempting to interpret 
the origin of other adaptations, similar to the 
former, except that the factor in question is not 
by the nature of the case apparently excluded 
from having any connection with them. 

But it cannot be said that this application of 
the “law of parsimony ”’ is altogether successful. 
It may recoil on those who use it. It might be 


168 DARWINISM AND HUMAN LIFE 


argued that there are some adaptive characters 
which cannot be readily interpreted in terms 
of natural selection (as is implied in the appeal 
of some Neo-Darwinians to “ intra-selection,”’ 
“ germinal selection,’ and so on), and that therefore 
natural selection cannot be regarded as a generally 
acting factor. Moreover, the Neo-Lamarckian is 
at liberty to reply that he does not regard the 
modification-inheritance theory as applicable to 
all possible cases. 

IMPORTANCE OF ENVIRONMENT AND FUNCTION 
Remains.—Although bodily changes due _ to 
changes in environment or in function may not 
be transmissible, the importance of these influences 
remains. (1) An inheritance cannot be realised 
without an environment, any more than a man 
whose legacy was a cheque could make much of 
it without a bank. (2) Changes in environment 
and function, saturating through the body, may 
stimulate the variability of the germ-plasm. This 
may be the cause of mutation. (3) Living creatures 
are In many cases very plastic, and their modifica- 
tions are often of great individual importance, 
and may even preserve the life. (4) The secondary 
effects of modifications may reach and influence 
the germ-cells. (5) Every one admits that the 
state of the maternal constitution is very important 
in all cases where there is an intimate connection 
between the mother and the unborn young. 

SELECTION AND STIMULUS.—In two other ways 
changes in the conditions of life are of great im- 
portance: they form part of the mechanism of 
selection, whereby the relatively less fit variants 
are quickly or slowly, roughly or gently, eliminated, 
and they act as a stimulus to the intrinsic self- 


FACTS OF INHERITANCE 169 


assertiveness and “ endeavour after well-being ” 
which characterise living creatures. We must 
advance beyond the conventional view that the 
environment is like a net closing in upon passive 
victims, which can only escape if they have been 
fitted by germinal variation (or acquired modifica- 
tion) to pass through some of the meshes; we 
must recognise, as a fact of life, what Lamarck 
and many others have discerned, that organisms 
actively assert themselves against this closing 
net, and by active endeavour (also, of course, a 
variational character when traced back) may 
win their way through. At certain levels every 
one is actively on the outlook for “a niche of 
organic opportunity.” In his “ Luck or Cunning ? ” 
Mr. Samuel Butler asked, ‘‘ Do animals and plants 
grow into conformity with their surroundings 
because they and their fathers take pains, or 
because their uncles and aunts go away?” The 
accurate answer is that the question is wrongly 
put, for even those who most believe in the 
negative importance of uncles and aunts going 
away will be willing to admit, likewise, the positive 
importance of “taking pains.” A rehabilitation 
of the Lamarckian position perhaps depends on 
making clear what the “effort ” of the creature 
amounts to, and what it really means. 

InprrEcT ImporTANcE oF MopDIFIcAaTIONs.— 
But there is another important consideration, 
which has been stated independently by Profs. 
Mark Baldwin, Lloyd Morgan, and H. F. Osborn, 
namely, that adaptive modifications may act as 
the fostering nurses of germinal variations in the 
same direction. We have referred to this else- 
where, but it may give greater completeness to 


170 DARWINISM AND HUMAN LIFE 


our survey if we quote a brief statement of the 
idea as expounded by Lloyd Morgan (“‘ Habit 
and Instinct’ (1896), p. 319): 

“ Persistent modification through many genera- 
tions, though not transmitted to the germ, neverthe- 
less affords the opportunity for germinal variation 
of like nature. 

“Suppose that a group of plastic organisms is 
placed under new conditions. Those whose innate 
plasticity is equal to the occasion are modified 
and survive. Those whose plasticity is not equal 
to the occasion are eliminated. .. . Such modifica- 
tion takes place generation after generation, but, 
as such, is not inherited. ... But any congenital 
variations similar in direction to these modifications 
will tend to support them and to favour the 
organism in which they occur. Thus will arise 
a congenital predisposition to the modifications 
in question. 

“The plasticity still continuing, the modifica- 
tions become yet further adaptive. Thus plastic 
modification leads, and germinal variation follows ; 
the one paves the way for the other. 

“The modification, as such, is not inherited, 
but is the condition under which congenital 
variations are favoured and given time to get a 
hold on the organism, and are thus enabled by 
degrees to reach the fully adaptive level.’ 

PRACTICAL [IMPORT OF THE QUESTION AS TO THE 
TRANSMISSIBILITY OF ACQUIRED CHARACTERS.— 
It is scarcely necessary to point out that the long- 
drawn-out discussion is one of great importance, 
affecting our whole theory of evolution, and even 
our everyday conduct. Herbert Spencer went 
the length of saying that “a right answer to the 


FACTS OF INHERITANCE 171 


question, whether acquired characters are or are 
not transmitted, underlies right beliefs, not only 
in biology and psychology, but also in education, 
ethics, and politics.” 

A modification is a definite change in the 
individual body, due to some change in “ nurture.” 
There is no secure evidence that any such individual 
gain or loss can be transmitted as such, or in any 
representative degree. How does this affect our 
estimate of the value of “nurture”? How should 
the sceptical or negative answer, which we believe 
to be the scientific one, affect our practice in regard 
to education, physical culture, amelioration of 
function, improvement of environment, and so on ? 

(a) Every inheritance requires an appropriate 
nurture if it is to realise itself in development. 
Nurture supplies the liberating stimuli necessary 
for the full expression of the inheritance. A 
man’s character as well as his physique is a function 
of “nature” and of “nurture.” In the language 
of the old Parable of the Talents, what is given 
must be traded with. A boy may be truly enough 
a chip of the old block, but how far he shows him- 
self such -depends on “nurture.” The conditions 
of nurture determine whether the expression of 
the inheritance is to be full or partial. It need 
hardly be said that the strength of an (inherited) 
individuality may be such that it expresses itself 
almost in the face of inappropriate nurture. History 
abounds in instances. As Goethe said, man is 
always achieving the impossible. Semon relates 
a pretty experiment with young acacias (Albizzia 
lophantha). They had never been exposed to the 
normal alternation of day and night, to which 
their race responds by expanding and closing the 


172 DARWINISM AND HUMAN LIFE 


leaves. Semon exposed them to artificial days and 
nights of six hours’ or twenty-four hours’ duration ; 
but the plants exhibited the twelve-hours’ cycle 
quite unmistakably—just a little altered. After 
this experiment Semon exposed the plants to 
continuous darkness or continuous illumination. 
The twelve-hours’ cycle still manifested itself for 
a time, but gradually became indistinct. Here 
we see the inherited nature struggling, as it were, 
against Inappropriate nurture. 

(b) Although modifications do not seem to be 
transmitted as such, or in any representative degree, 
there 1s no doubt that they or their secondary 
results may in some cases affect the offspring. 
This is especially the case in typical mammals, 
where there is before birth a prolonged (placental) 
connection between the mother and the unborn 
young. In such cases the offspring 1s for a time 
almost part of the maternal body, and hable to be 
affected by modifications thereof—e.g. by good 
or bad nutritive conditions. In other cases, also, 
it may be that deeply saturating parental modifica- 
tions, such as the results of alcoholic and other 
poisoning, affect the germ-cells, and thus the 
offspring. A disease may saturate the body with 
toxins and waste-products, and these may provoke 
prejudicial germinal variations. 

(c) Though modifications due to changed 
“nurture ” do not seem to be transmissible, they 
may be reimpressed on each generation. Thus 
“nurture ” becomes not less, but more, important 
in our eyes. “Is my grandfather’s environment 
not my heredity?” asks an American author 
quaintly and pathetically. Well, if not, let us 
secure for ourselves and for our children those 


FACTS OF INHERITANCE 173 


6 


factors in the “ grandfather’s environment ”’ that 
made for progressive evolution, and eschew those 
that tended elsewhere. 

Are modifications due to changed nurture not 
entailed on offspring ? Perhaps it is just as well, 
for we are novices at nurturing even yet. More- 
over, the non-transmissibility cuts both ways: if 
individual modificational gains are not handed on, 
neither are the losses. 

Is the “ nature ’—the germinal constitution, to 
wit, all that passes from generation to generation— 
the capital sum without the results of individual 
usury ? Then we are freed, at least, from undue 
pessimism, because of the many harmful functions 
and environments that disfigure our civilisation. 
Many detrimental acquired characters are to be 
seen all around us, but if they are not transmissible, 
they need not last. 

(d) The plasticity of the organism admits of 
definite modifications being reimpressed on succes- 
sive generations of individuals, and this is the more 
important when we consider what has been said 
in the section on “ The Indirect Importance of 
Modifications.” They may serve as modificational 
screens until comcident variations in the same 
direction can emerge and establish themselves. 
This also cuts both ways in human societies, where 
natural selection is interfered with, and where 
naturally prejudicial deviations from the norm are 
not necessarily punished by elimination. 

(e) Of particular importance is the fact that 
man, in contrast to other creatures, has developed 
around him an external heritage, a social framework 
of customs and traditions, of laws and institutions, 
of literature and art, by which results almost 


174 DARWINISM AND HUMAN LIFE 


equivalent to the organic transmission of certain 
kinds of modifications may be brought about. 

(f) Is there not some result of the almost tire- 
some controversy on “ the inheritance of acquired 
characters,” if we are thereby freed from indulging 
in false hopes, but are forced to the conviction 
that “nurture” is more important than ever ? 
Although what is “ acquired’? may not be in- 
herited, what is not inherited may be acquired. 
Thus we are led to direct our energies even more 
strenuously to the business of reimpressing desir- 
able modifications, and therefore to developing 
our functions and environments in the direction 
of progress. 

It may be, however, that our methods must 
change with the change in our expectations. For 
though we can, by modification, directly influence 
the individual, and in some measure even control 
the expression of his inheritance, it is not through 
modifications that we can hope directly to influence 
posterity. Man is a slowly reproducing, slowly 
varying organism. What is above all precious is 
the conservation of good stock. No number of 
veneering modifications—superficial screens of or- 
ganic defects—can atone for allowing a deteriora- 
tion of the germinal inheritance to diffuse itself 
or to accumulate. For progress which is really 
organic—for progress, that is, in our natural 
inheritance—we must wait, or rather work, 
patiently. 

Even when it is impossible to do much, there is 
practical importance in accuracy—which 1s greatly 
needed in connection with human heredity. How 
slow of dying is, for instance, the fallacy that ancient 
and powerful families are necessarily degenerate. 


FACTS OF INHERITANCE 175 


In spite of what Galton and other careful workers 
have said, it is persistently asserted that noble 
and illustrious families usually end in sterility— 
a mistake largely due to ignoring the female lines 
of descent. 

INHERITANCE OF Morat CuHaracter.—In the 
development of “ character’? much depends upon 
early nurture, education, and surrounding in- 
fluences generally, but how the individual reacts to 
these must largely depend on his inheritance. 
Truly the individual himself makes his own 
character, but what does that mean but the’ 
habitual adjustment of an hereditarily determined 
constitution to surrounding influence? Nurture 
supplies the stimulus for the expression of the 
moral inheritance, and how far the inheritance 
can express itself depends on the nurture-stimuli 
available just as surely as the result of nurture 1s 
conditioned by the hereditarily determined nature 
on which it operates. It may be urged that 
character, being a product of habitual modes of 
feeling, thinking, and acting, cannot be spoken of 
as inherited, but bodily character is similarly a 
product dependent upon vital experience. Some 
children are “born good” or “ born bad,” just 
as some children are born strong and others weak, 
some energetic and others “tired” or “ old.” 

It is entirely useless to boggle over the difficulty 
that we are unable to conceive how dispositions for 
good or ill lie implicit within the protoplasmic unit 
in which the individual life begins. The fact is 
undoubted that the initiatives of moral character 
are in some degree transmissible, though, from the 
nature of the case, the influences of education, 
example, environment, and the like, are here more 


176 DARWINISM AND HUMAN LIFE 


potent than in regard to structural features. We 
cannot make a silk purse out of a sow’s ear, though 
the plasticity of character under nurture is a fact 
which gives us all hope. Explain it we cannot, 
but the transmission of the raw material of 
character is a fact, and we must still say, with Sir 
Thomas Browne: “ Bless not thyself that thou 
wert born in Athens; but, among thy multiplied 
acknowledgments, lift up one hand to heaven 
that thou wert born of honest parents, that 
modesty, humility, and veracity lay in the same 
egg, and came into the world with thee.” 

THREE GENERAL Conciusions.—(1) The study 
of inheritance is apt to leave a fatalistic impression 
in the mind, and to some extent this is justified. 
We cannot get away from our inheritance. As 
the poet Heine said, half laughingly half bitterly: 
‘A man should be very careful in the selection of 
his parents.” On the other hand, looking forward, 
we may change the word “ parent ”’ into “ partner,” 
recognising that a good inheritance is the most 
precious of all possessions, and that 1t should be 
guarded from mixture with bad stock. 

(2) But, again, the conclusion 1s strongly borne 
in on us that a good nurture 1s the necessary comple- 
ment of a good nature and the individual corrective 
of a poor nature. 

(3) If there is little or no scientific warrant for 
our being other than extremely sceptical at present 
as to the inheritance of acquired characters—or 
better, the transmission of modifications—this 
scepticism lends greater importance than ever, on 
the one hand, to a good “ nature,” to secure which 
is the business of careful mating ; and, on the other 
hand, to a good “ nurture,” to secure which for our 


FACTS OF INHERITANCE Lit 


children is one of the most obvious and binding 
duties : the hopefulness of the task resting especi- 
ally upon the fact that, unlike the beasts that 
perish, man has a lasting external heritage of 
ideas and ideals, embodied in prose and verse, in 
statue and painting, in cathedral and university, 
in tradition and convention, and above all in 
society itself. 





CHAPTER VI 
SELECTION: ORGANIC AND SOCIAL 


179 


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CHAPTER VI 


SELECTION : ORGANIC AND SOCIAL 


Influence of Malthus—Darwin’s Position—The Theory stated—The 
Theory of Natural Selection to be tested as an Interpretative 
Formula—tIllustrations of Natural Selection—Objections and 
Crtticisms—Adaptations—Changes_ since Darwin’s Day— 
Evidences of Natural Selection—Lessening the Burden of the 
Theory—Sexual Selection—Isolation—Gradual Diminution of 
Natural Selection in Mankind—Contrast between the Human 
Race and the Animal World—Some Natural Selectien 
persists in Mankind—The Dilemma of Civilisation—The ex- 
treme laissez-faire Position—Social Surgery—Is Social Selec- 
tion compensating for Diminished Natural Selection ?— 
Reversed Selection in Human Soeiety—Practical Considerations 
—Summary of the General Argument in regard to Human 
Selection—Constructive Suggestions—Selection of Eutopias— 
Selection of Healthful Occupations—Eugenic Selection, 


Darwin is often called the Newton of biology, 
though some say he was rather its Copernicus. 
In any case, he discerned in nature the working of 
a great process, which has helped us to understand 
how things have come to be as they are. Among 
his services there is none greater than this, that he 
discovered the efficacy of Natural Selection, whieh 
means Nature’s sifting. The raw materials are 
inborn variations; the internal condition is the 
heritability of the favourable variations; the 
external condition is the struggle for existence ; 
the process of sifting is discriminate elimination ; 
the result is the survival of the fittest to the given 
conditions. 

INFLUENCE oF Matruus.—Adumbrations of the 

181 


182 DARWINISM AND HUMAN LIFE 


general idea of selection are to be found in various 
pre-Darwinian documents,’ but it was to Malthus 
only that Darwin, who was very generous in dealing 
with anticipations, owned any debt. He speaks 
of this in a well-known passage in his ‘“ Autobio- 
graphy ’’: “ In October, 1838, fifteen months after 
I had begun my systematic inquiry, I happened 
to read for amusement * Malthus on Population,’ 
and, being well prepared to appreciate the struggle 
for existence which everywhere goes on from 
long-continued observations of the habits of animals 
and plants, it at once struck me that, under these 
circumstances, favourable variations would tend 
to be preserved and unfavourable ones to be 
destroyed. The result of this would be the forma- 
tion of new species. Here, then, I had at last gota 
theory by which to work.” 

Twenty years after—Darwin having published no 
theory meanwhile—history repeated itself. Alfred 
Russel Wallace was collecting insects at Ternate 
and sufferimg badly from fever. As he was resting 
one day between fits, he happened to recall Malthus’ 
“Principles of Population” which he had read 
about twelve years before—the first book that he 
had come across approaching philosophical biology. 
He thought of what Malthus had said regarding 
the way disease, famine, and war keep down the 
population of savage races to a much lower average 
than that of civilised peoples; he thought of the 
similar elimination that goes on in the animal 
world, and it occurred to him to ask the question, 
“Why do some die and some live?” “ And the 
answer was, Clearly, that on the whole the best 
fitted live. From the effects of disease the most 


1 E.g. by Charles Wells, Patrick Matthew, James Cowles Prichard. 


SELECTION: ORGANIC AND SOCIAL 183 


healthy escaped; from enemies, the strongest, 
the swiftest, or the most cunning; from famine, 
the best hunters or those with the best digestion ; 
and so on. Then it suddenly flashed upon me 
that this self-acting process would necessarily 
umprove the race, because in every generation the 
inferior would inevitably be killed off and the 
superior—that is, the fittes:—would survive. Then 
at once I seemed to see the whole effect of this. ...” 
His words in the 1858 paper were: “ If any species 
should produce a variety having slightly increased 
powers of preserving existence, that variety must 
inevitably in time acquire a superiority in numbers.” 
Thus, for the second time, from the domain of 
human society the idea of natural selection was 
suggested. 

Perhaps the suggestion was made a third time, 
for it is an interesting fact that in 1852—six years 
before the theory of natural selection was launched 
by Darwin and Wallace, when Herbert Spencer 
wrote his famous evolutionist article on ‘“ The 
Development Hypothesis,’ he published another 
important essay entitled, “A Theory of Popula- 
tion,’ toward the close of which he came within an 
ace of recognising that the struggle for existence 
was a factor in organic evolution. Spencer was 
not guilty of reading much, but it would be striking 
if he too had been stimulated by Malthus. In any 
case we have the fact that, at a time when pressure 
of population was practically interesting men’s 
minds, Darwin, Wallace, and Spencer were in- 
dependently led towards a theory of organic 
evolution. There could be no better illustration 
of the Comtian thesis that science is a socal 
phenomenon. Prof. Patrick Geddes suggests that 


184 DARWINISM AND HUMAN LIFE 


the severity of industrial competition, which had 
increased bitterly between Malthus’s time and 
Darwin’s, was at least subconsciously in the mind 
of both Darwin and Wallace, and gave spring to 
the theory which they projected upon nature.’ 
Darwin’s Posttion.—Let us try to understand 
Darwin’s problem. His studies as a naturalist 
had made him acquainted with a large number of 
animals and plants, and two facts had especially 
impressed him: first, that the various kinds are 
suited to the niches which they fill—suited often 
as hand to glove; and second, that in many cases 
the various kinds are closely linked together by 
resemblances which evidently mean blood-relation- 
ship. What Darwin wished to get at was a theory 
of the origin of one species from another, and a 
theory of the origin of the adaptations with which 
the world of life is full. He found the answer to 
both his questions in discovering a process actually 
at work—Nature’s sifting of the changes that crop 
up. He defined it as “the preservation, during 
the battle for life, of varieties which possess any 
advantage in structure, constitution, or instinct.” 

1 Following Bacon, we may draw a useful distinction between 
a scientific theory in the stage of suggestion—an anticipation of 
nature, and a scientific theory in the stage of verification—an inter- 
pretation of nature. In the stage of suggestion the theory of 
natural selection was in greater part sociomorphic; but it passed, 
by Darwin’s careful workmanship, into the stage of verification, 
and it should be remembered that the validity of a scientific theory 
is not affected by what suggested it. A theory is to be estimated 
by its power of formulating a definite order of facts. 

At the same time those who insist on using the formula of natural 
selection in the interpretation of human affairs, and who call it 
a brological formula, must remember the history—that it was from 
the human domain that the suggestion of the theory came. Per- 


haps there is some supplementary suggestion from human society, 
equally valuable, which no Darwin has yet arisen to appreciate. 


SELECTION: ORGANIC AND SOCIAL 185 


His general line of thought was something like 
this. The gardener and the breeder watch for 
changes or variations ; they select for propagation 
those variants that please them, keeping all others 
away; gradually they establish new varieties that, 
breed true. So it is in nature, Darwin said, where 
variations are continually croppmg up. But what 
takes the place of the breeder? Nature’s sifting 
in the struggle for existence. Man has done much 
in a short time; what may Nature not have 
done in a long time? As has often been pointed 
out, there are some differences in detail between 
artificial and natural selection, but the essential 
features are the same. 

“The theory of natural selection,’ Mr. Wallace 
writes,' “commonly called Darwinism, is one of 
the most simple and easy of comprehension in the 
whole range of science; yet, after fifty years of 
continuous exposition and study, there is perhaps 
none that 1s so widely and persistently misunder- 
stood.” Let us therefore linger over it. 

When one visits that scientific Aladdin’s cave 
called the British Museum (Natural History), one 
is impressed, on entering, by the statue of Darwin, 
and from it the eye falls to a tree full of pigeons 
with the wild rock-dove (Columba livia) as a centre, 
and on the branches round about Pouters and 
Carriers, Tumblers and Trumpeters, Jacobins and 
Fantails, and other breeds. That case of pigeons 
is a Darwinian diagram, for Darwin chose these 
birds for special study—and they led him to a 
goal as famous as Ararat. There are over two 
hundred very well-marked breeds of domestic 
pigeons, and there are at least ten that would be 

1 Fortnightly Review (March 1909), p. 411. 


186 DARWINISM AND HUMAN LIFE 


ranked as distinct genera if they occurred wild. 
Yet there is strong evidence that all are scions 
of the blue rock-pigeon (Columba lina). Darwin 
pointed out that the social, non-arboreal habits, 
the mode of cooing, and other characters of 
domestic pigeons, point to Columba livia; that 
this bird has a wide range of distribution; that 
it is very variable in plumage, easily tamed, and 
actually domesticated ; that all races of domestic 
pigeons are fertile when crossed, and their off- 
spring are usually fertile—two facts which point 
to one origin for all;. that all domestic pigeons 
tend to revert to the blue rock-ptgeon; and 
so on. 

In the same way, as is well known, Darwin 
brought forward evidence that all the breeds of 
poultry—Hamburghs and Dorkings, Bantams and 
Silk-fowl, and all the rest of them—are descended 
from the jungle-fowl, Gallus bankiva, which is 
still found wild in some parts of India and the 
Malay Islands. There seems to be evidence that 
the jungle-fowl—which our gamecock most nearly 
resembles—was domesticated in the East before 
1400 B.c., and was introduced into Europe about 
600 B.c. The clear cases of pigeon and fowl were 
backed up by more difficult cases, such as those 
of horse and dog, where 1t seems almost certain 
that the domesticated breeds have arisen from 
several distinct wild species. 

At all events, Darwin proved, up to the hilt, that 
the breeder is a transformist. Circe changed men 
into pigs; the prehistoric breeders made a wolfish 
creature into a trustworthy guardian of their 
flocks. What is the method? The breeder can- 
not create ; he waits for what turns up, and then he 


SELECTION: ORGANIC AND SOCIAL 187 


directs. He directs by bringing similars together 
and by eliminating undesirables from the flock 
or herd. So Nature directs—but automatically 
—by singling and sifting in the struggle for 
existence. 

Tue Turory Statep.—(1) Darwin started with 
the fountain of change within the living creature, 
whence variations are always welling forth. Off- 
spring are not quite like their parents, or like one 
another. It is a fact that there are individual 
variations, for better and for worse, between living 
creatures of the same kind. In some cases it is 
definitely known that these variations may be 
transmitted. 

(2) Life is very prolific, and in every kind of 
living creature—except man—the majority die 
young. There is not usually any increase in 
numbers from generation to generation. There 
is a ceaseless struggle for existence—a phrase to 
be taken in a wide and metaphorical sense as a 
description of what goes on in nature because of 
the limits of space and the self-assertiveness of the 
individual, because of the prolific multiplication 
of the eaters and the imsufficiently rapid supply of 
the eatable, because of the changeful and merciless 
physical environment, and all the subtle interrela- 
tions of things in the web of life, whose warp and 
woof are love and hunger. 

It is very important to realise the web of life 
in this connection, for, as an acute critic points out, 
it alone warrants us in believing that “ slight 
differences may give one creature an advantage 
over its neighbour in a nicely balanced struggle for 
life. In other words, it introduces the conception 
of a correlation between even minute variations and 


188 DARWINISM AND HUMAN LIFE 


the survival or non-survival of their possessors.” ? 
As Darwin says, in a notable passage: “ Battle 
within battle must be continually recurring, with 
varying success; and yet, in the long run, the 
forces are so nicely balanced that the merest trifle 
would give the victory to one organic being over 
another.” 

(3) The theory continues, that, if variations occur 
in the direction of increased fitness, and if the 
variations are heritable, and if there is discriminate 
elimination with reference to these variations, 
then the possessors of the fitter variations must be 
favoured with longer life and larger families—with 
survival, in short. And if this is kept up con- 
sistently, then new adaptations, and, with the help 
of isolation, new species, will arise. Those mem- 
bers of a species that are handicapped will become 
a minority and eventually their type will be 
eliminated. Those that have varied so as to be in 
any appreciable way favoured will become the 
majority, and eventually the type, of the species. 

A little reflection will show that there are two 
main modes of natural selection. It may produce 
its effects by the discriminate elimination of the 
less fit, or by the increased and more effective 
reproductivity incident on the success of the more 
fit. These two modes are sometimes distinguished 
as Lethal and Reproductive Selection respectively. 
In both cases the fitter members of a generation 
contribute more than the less fit to the next genera- 
tion. If we regard sexual selection as a special 
case of natural selection, which seems the clearest 
view, we have to include extreme cases like that 


1 “Evidence of Natural Selection,” by E. 8S. Russell, in Revista 
dt Sctenza (1908), vol. iii. 


SELECTION: ORGANIC AND SOCIAL 189 


of the single drone that overtakes the queen-bee 
in her nuptial flight—all the others being left to 
die non-reproductive. 

Darwin summed up the theory in a couple of 
sentences: “*As many more individuals of each 
species are born than can possibly survive, and 
as, consequently, there is frequently recurring 
struggle for existence, it follows that any being, 
if it vary however slightly in any manner profitable 
to itself, under the complex and sometimes varying 
conditions of life, will have a better chance of 
surviving, and thus be naturally selected. From 
the strong principle of inheritance any selected 
variety will tend to propagate its new and modified 
form.”’ 

Tue THErory or NaTuRAL SELECTION TO BE 
TESTED AS AN INTERPRETATIVE [ormMuLA.—For 
what has occurred in the past the theory of natural 
selection can never be proved; we can only show 
that it offers a reasonable interpretation, that it is 
a formula that fits. In the case of many of the 
most remarkable adaptations, such as those of 
mimicry and protective resemblance, it 1s the only 
interpretation in the field that has any approach to 
feasibility. 

In regard to what is going on at present, several 
attempts have been made (as we shall see later) 
to catch natural selection at work, to prove the 
occurrence of discriminate elimination with refer- 
ence to a particular character, to show that what 
determines that one organism should be taken 
and another left is that the first lacked something 
which the survivor has. This is extremely im- 
portant, for it 1s “ as easy as winking ”’ to imagine 
possible utilities for a particular character, whereas 


x ’ 


199 DARWINISM AND HUMAN LIFE 


it is our business to prove that the survivors survive 
because they have the character in question. 

ILLUSTRATIONS oF Narurat Sexection.—In the 
1858 essay Darwin gave the following imaginary 
illustration. Some dog-like animal lives on rabbits, 
and on hares, when it can get them; the rabbits 
become scarcer, and the hares more plentiful, so 
the carnivore turns its attention to hares; those 
carnivores that varied in the direction of swiftness 
and sharp-sightedness would get on best, would be 
more successful as regards numbers and vigour of 
ofispring; in a thousand generations there would 
be a marked effect—as surely, he said, as grey- 
hounds can be improved by selection and careful 
breeding. 

Many insects in Madeira have reduced and 
useless wings, or none, while their allies in Kurope 
have them well developed. The Darwinian inter- 
pretation is, that as Madeira, like similar islands, 
is exposed to sudden gales, the flying insects have 
been blown out to sea, while those that varied in 
the direction of flightlessness have survived. It 
is easy to make fun of this, as Samuel Butler did | 
when he said it was like explainmg our own 
presence by the fact that our cousins, uncles, and 
aunts had gone away. A little reflection, however, 
will show that the theory fits the facts, and our 
confidence in the interpretation grows when we 
find that other exposed and wind-swept islands 
agree with Madeira in having flightless insects. 
Thus, in the stormy and shelterless Kerguelen all 
the insects (including a moth, several flies, and 
many beetles) are flightless and most are wingless. 

Many Arctic mammals and birds—such as fox 
and faleon—have a beautiful white colour: what 


SELECTION: ORGANIC AND SOCIAL 191 


is the selectionist interpretation of this charac- 
teristic ? The first step is to recognise that animals 
are very variable as regards colouring, and thus 
there is raw material to workon. Furthermore, a 
variation in the direction of whiteness is common— 
white blackbirds and swallows, white rats and 
moles, being well known. It seems likely that a 
ferment essential to the manufacture of the pig- 
ment drops out of the inheritance of these 
albinos. The change is of germinal origin, and 
it is hereditary. Now there is a keen struggle 
for existence in Arctic regions, and any character 
that gives its possessor a pull is likely to have 
selective value. But there are various advan- 
tages in a white dress in snowy regions—it is 
the least conspicuous and the most comfortable. 
Those who turn white will get on best, other things 
being equal. Therefore we have white races in 
Arctic regions, and we may corroborate the 
argument by referring to a simple experiment. 
Prof. Davenport had 300 chickens in a field, 80 
per cent. white or black and conspicuous, 20 per 
cent. spotted and inconspicuous. In a short time 
twenty-four were killed by crows, but only one 
of the killed was spotted. 

In a heavy snowstorm at Johannesburg in 
August 1909, many hundreds of trees were destroyed 
by the weight of snow on the branches. It was 
interesting, after the storm, to notice that the 
elimination was in a marked degree discriminate. 
The trees that suffered most were the imported 
Australian trees, such as Blue Gums and Black 
Wattles, quickly growing, with soft wood, and 
with abundant foliage that caught the snow. On 
the other hand, the deodars from the Himalaya 


192 DARWINISM AND HUMAN LIFE 


Mountains, constitutionally adapted to let the 
snow slide from their pendulous branches and 
acicular leaves, had hardly a twig broken. If 
similar storms occurred several times a year, instead 
of once in twenty years, there would soon be no 
Blue Gums or Wattles. 

OBJECTIONS AND CriticisMs.—Darwin’s sugges- 
tion was that new adaptations, new varieties, new 
species have arisen by the elimination of the 
relatively unfit variants and by the selection of 
the relatively fit. In other words, natural selection 
is the main directive factor in evolution. That is 
to say, given variations, the secret of success is 
sifting. Against this theory all manner of objec- 
tions have been urged—fair and unfair, competent 
and incompetent, wise and foolish. The army of 
objections is so huge that one feels there must be 
strong virtue in a theory that is so vigorous after 
fifty years. It should always be remembered 
that the best and the severest critic of the theory 
of natural selection was Charles Darwin himself. 
We do not propose to defend the theory or to 
slay the thrice slain, but the following statements 
may serve to remove some common misunder- 
standings. 

(1) It must be clearly understood that the 
fittest ’’ which survive are not necessarily best 
or highest on any absolute standard, but simply 
fittest for the given conditions. The liver-fluke is 
fit,” as well as the sheep. Though the trend of 
evolution has been on the whole progressive, the 
tapeworm is as well-adapted to its inglorious lot 
as is the lark at heaven’s gate. 

(2) Until we know more about the origin of 
the variations which form the raw material of 





SELECTION: ORGANIC AND SOCIAL 193 


progress we are open to the reproach of giving 
a theory of the survival, but not of the arrival 
of the fittest. Yet there are often two misunder- 
standings in the minds of those who play with 
this reproach, which Darwin met long ago. (a) It 
is, of course, clear that natural selection is Siva, 
the Destroyer, and that L’Hvolution créatrice is 
the secret of the organism. Natural selection 
prunes a growing and changeful tree. Natural 
selection is a directive, not an originative, factor. 
The problem of origins is the problem of variation. 
(4) It must also be noted that, if the fittest have 
arisen by very gradual steps, by the accumulation 
of variations small in amount, then the reproach 
of explaining, not the arrival, but only the survival, 
loses much of its force. 

(3) With unwearying reiteration the objection 
is raised that the initial stages of new adaptations 
will be too minute to have survival value. This 
difficulty has been often dealt with, and it may 
suffice here to point out (a) that no one can 
decide, in ana priory way, how small a change may 
be of critical moment; (b) that in the fine texture 
of the web of life a trivial difference, as Darwin 
said, may determine survival; (c) that elimination 
may be effective though it 1s not accomplished in 
a generation; and (d) that an incipient change 


1 Most biologists admit, what Darwin himself clearly recognised, 
that in strictness the real process is natural elimination. As an 
American biologist says: ‘‘ The fit are not selected—it is the unfit 
who fail to survive, and the fit are merely the survivors. The 
process is negative throughout. A railway train selects its pas- 
sengers in the same sense—those who come in time get aboard, 
those who do not, get left.” At the same time, though the process 
is negative, the results are in part positive. In eliminating the 
weak and noxious Natural Selection is a conservative agency. 13 


194 DARWINISM AND HUMAN LIFE 


may be carried through its initial stages by being 
correlated with another more important change. 
(4) The eliminative processes that most Dar- 
winians believe in, because they see them going 
on, may be slow as well as quick, gentle as well 
as severe, environmental as well as competitive. 
The selected are not necessarily those saved from 
the jaws of violent death; they may be simply 
those who, in virtue of a heritable peculiarity, have 
a rather longer and more successful life and a 
rather larger and more successful family. The 
only eliminative processes that can be believed 
in as counting for much in evolution are those 
which are discriminate and consistent. Thinning 
turnips may serve as our diagram of indiscriminate 
elimination (only very indirectly does 1t improve 
the turnip race); Luther Burbank carefully 
burning some of his most interesting creations 
because they are not quite right for his purpose 
may serve as our diagram of discriminate elimina- 
tion. But while the modes of natural selection 
are many and various, the logic of the process 
is always the same—when a heritable peculiarity 
is of critical moment in favouring survival it will 
tend to persist, provided (a) that its occurrence 
is sufficiently frequent, and (6) that the dis- 
criminate selection fostering 1t 1s kept up con- 
sistently for a long enough period. 
Apaprations.—No one can nghtly appreciate 
the theory of natural selection who does not 
realise in some measure the universal occurrence 
of those detailed fitnesses of structure and function 
which are called adaptations." The general idea 


1 We use the word adaptation to express a result achieved ; it is 
sometimes used to express the process of reaching that result. 


SELECTION: ORGANIC AND SOCIAL 195 


of fitness is familiar; we are irresistibly pleased 
in our own affairs with arrangements like safety- 
valves and regulators which bring about important 
results in an effective way; we pour contempt on 
tools that will not work, on machines that will not 
- go. But we have not to travel beyond our own 
bodies to find illustrations of safety-valves and 
regulators that put to scorn all machinery, and 
one of the perennial delights of natural history, 
in the wide sense, is its continual discovery of 
fresh instances of hand-and-glove adaptations. 
There is wonderful fitness even in one of the 
lowest forms of life—it is always changing and yet 
it remains the same, it answers back effectively 
to external stimuli, it grows and passes from one 
phase to another, it reproduces itself, and it is 
said that some of the simplest never die. We 
cannot, at present, get behind this primary 
adaptiweness of living creatures—it is implied in 
what we mean by living. Itis convenient, however, 
to keep the word “adaptation ”’ for something 
super-added to what we must take for granted, 
and yet it is difficult to draw the line. The power 
of growth is a primary attribute; the capacity of 
regrowing a readily broken limb depends on 
this; and yet it is difficult to understand why, 
for instance, a chameleon should not be able to 
regrow its tail, as almost all other hzards can do, 
unless we regard the distribution of the regenerative 
capacity as adaptive, adjusted in the course of 
ages to frequently recurrent needs. We say that 
the immunity which certain organisms have to 
certain poisons is an adaptation, it has been 
wrought out and added on; but is it not, perhaps, 
a special case of the immunity which even simple 


196 DARWINISM AND HUMAN LIFE 


organisms have to considerable accumulations of 
their own self-made poisons or waste-products ? 

To illustrate adaptations Weismann takes, for 
instance, the whale-type among mammals, and 
refers to “the fish-like form of the body, the 
hairlessness of the skin, the transformation of 
the fore-limbs to flippers, the disappearance of 
the hind-limbs and the development of tail-flukes, 
the layer of blubber under the skin, which affords 
the protection from cold necessary to a warm- 
blooded animal,” and so on through a long list. 
The whale is a great bundle of adaptations to 
a mode of life which is peculiar for a mammal. 

Whether we take actively functional parts, 
such as our own hand, or passively functional 
structures, such as a feather; whether we take 
obvious features, such as the typical spindle-like 
shape of fishes, or more recondite features, such as 
the structure of a bone; whether we take mimicry 
or migration, ‘ wherever we tap organic nature,” 
as Romanes said, “it seems to flow with purpose.” 

Natural selection is the theory of the indirect 
coming about of this wide-spread purposiveness— 
the possibility of variations in the direction of 
fitness being granted. Lamarckism, which assumes 
the hereditary accumulation of functional and 
environmental modifications, is a theory of direct 
adaptation—on the whole simpler than the selection 
theory, but suffering from the serious disadvantage 
that its fundamental assumption is still without 
cogent evidence in its favour. 

Birds’ eggs are of diverse shapes, and we know 
in some detail the actual factors which determine 
these. We also know that individual variations 
in the shape are not uncommon. We can under- 


SELECTION: ORGANIC AND SOCIAL 197 


stand, then, that if a certain shape were particularly 
well suited for special conditions, that shape would 
be selected, z.e. the birds that were constitutionally 
unable to lay eggs of the fit shape would be 
eliminated. Now Darwin points out that, in 
sea-birds like guillemots and razor-bills, which 
lay their eggs on the narrow ledges of precipitous 
cliffs, the shape of egg is very markedly top-like. 
The adaptiveness of the shape is that, if the egg 
be jostled by the parent or some other bird, or 
be caught in a swirl of wind, it rotates on its 
short axis without rolling from its original position. 

Let us take another instance. The Alsop prawn 
(Hippolyte varians) may be red, yellow, blue, 
orange, olive, violet, brown, green, and other 
colours. It is born without a bias and it takes 
on the colour of its surroundings, both when 
young and when adult. Put some in a glass 
aquarium, and line the sides and floor with paper 
of almost any colour; the prawn follows, and 
from one colour it may be changed to any other. 

As bright yellow, blue, and violet are not 
common colours among the seaweed, it has been 
argued that the power of colour-change cannot be 
the outcome of selection. But that is an absurd 
conclusion; it is by no means certain that the 
bright colours are absent among seaweed, and, 
besides, adaptiveness is rarely perfect. 

Many colour-adaptations are very striking. Thus 
Prof. Poulton has shown that certain caterpillars 
will, within certain limits, take on the colour 
of their surroundings, and Engelmann has shown 
that the peculiar alge known as Oscillatoria 
become green in red light, red in green light— 
physiologically tLe best possible colours. 


198 DARWINISM AND HUMAN LIFE 


We may speak of an organism as a bundle of 
adaptations, but we are not justified in saying that 
every structure is an adaptation. There are some 
structures whose use 1s unknown, and there are 
others which seem to be of no value, such as well- 
concealed decorativeness. It may be, however, 
that some of the details whose significance is 
unknown are the architectural correlates of im- 
portant characters. 

CHANGES SINCE Darwin’s Day.—Darwin did not 
doubt the legitimacy of supposing that some of 
the direct eflects of use and disuse and of the 
influence of surroundings may be transmitted as 
such or in a representative degree. He was, 
therefore, to a limited extent a Lamarckian, and 
there are some competent authorities who occupy 
a similar position. We are far from dogmatically 
declaring that the Lamarckian position is quite 
untenable, but we have hinted at some of the 
difficulties which have led us to abandon it until 
further evidence is forthcoming. 

Leaving this as a drawn battle, we wish to 
refer briefly to two marked changes since Darwin’s 
day. In the first place, there has been a useful 
attempt to give some experimental demonstration 
of the working of natural selection. In the 
second place, there is a growing feeling among 
different bodies of workers that it is not necessary 
to burden the shoulders of the natural selection 
theory so heavily as heretofore. 

Evipences or Naruran SELection.—One of 
the most interestng—though, from the nature of 
the case, least impressive—steps of progress since 
Darwin’s day is the attempt to secure definite 
evidence of the operation of natural selection. 


SELECTION: ORGANIC AND SOCIAL 199 


It must be admitted that Darwin left the theory 
in this form: Variations occur abundantly ; there 
is a complex, subtle struggle for existence; there is 
a constant process of sifting and winnowing; if fit 
variations occur among the rest, and if there is 
discriminate elimination so intense that survival 
depends on the presence or absence of the variation 
in question, then new adaptations must result. 
Those who have something of a naturalist’s ex- 
perience and have some appreciation of the enor- 
mous scale upon which Nature works—as to time, 
as to numbers, as to chances—have usually been 
content to accept this theory of natural selection 
as a good working hypothesis. 

But what we wish is actual proof of discriminate 
elimination, that survivors do survive in virtue of 
particular qualities. A few illustrations in the 
present may legitimise our belief that similar 
processes occurred in the past. Let us summarise 
the best of these illustrations. , 

With silk threads Cesnola! tethered forty-five 
green praying mantises to green herbage, and sixty- 
five of the brown variety to withered plants. He 
watched them for seventeen days, and all survived 
unnoticed by birds. But when he put twenty-five 
green ones among brown herbage all were killed 
by birds in eleven days, while of forty-five brown 
ones on green grass, only ten survived at the end 
of seventeen days. Here we have definite proof of 
a selective death-rate, definite proof of the selective 
value of the protective coloration. 

Pouiton and Sanders * fastened 600 pupze of the 

1 See “‘ Biomctrika,”’ vol. iii. p. 58. 


2 « Report of the British Association, Bristol Meeting” (1899). 
pp. 906-909, 


200 DARWINISM AND HUMAN LIFE 


tortoise-shell butterfly (Vanessa urtice) to nettles, 
tree-trunks, fences, walls, and so on. At Oxford 
there was a mortality of 93 per cent., pointing to 
an extremely high elimination-rate, and the only 
pup that survived were on nettles, where they 
were least conspicuous. At St. Helens, in the Isle 
of Wight, the elimination was 92 per cent. on fences 
where the pups were conspicuous, as against 
57 per cent. among nettles where they were incon- 
spicuous. Here, again, there is definite evidence of 
discriminate elimination. 

Another illustration 1s to be found in the late 
Prof. Weldon’s! well-known experiments on crabs. 
He placed 248 male shore-crabs (Carcinus menas) 
in a vessel of sea-water containing In suspension 
a quantity of china-clay; and 94 survived. It was 
found that the mean of the frontal breadths of 
the survivors was distinctly smaller than that of 
the eliminated. ‘A difference in the mean value 
of a character between survivors and eliminated, 
when both have been exposed to rdentical environ- 
mental conditions, is proof that the character is 
being acted upon by natural selection. . . .”? That 
is, by the ordinary “ secular selection,” for there 
is another mode—" periodic selection,” in which 
the mean value of the character is not changed, 
but extreme deviations from the mean are lopped 
off. ‘* Periodic selection” can be detected by the 
decrease in the range of variability. 

Measuring small specimens (10-15 mm.) of 
shore-crab taken from Plymouth Sound, in the 


1 «Proc. Royal Soc.” (1895), vol. lvii. pp. 360-79. Also Nature 
(1898), vol. lviii. pp. 499-506 and 595-6. 

2 See “ The Evidence of Natural Selection,’ by E. S. Russell, 
in Rivista di Scienza (1908), vol. iii. Le 


SELECTION: ORGANIC AND SOCIAL 201 
years 1893, 1895, and 1898, Prof. Weldon found 


that, during the time between the first measure- 
ment and the last, the frontal breadth of the crabs, 
taken relatively to their length, had distinctly 
decreased. As the amount of suspended clay and 
sewage in Plymouth Sound had increased during 
the same period, Prof. Weldon concluded that 
those with broad fronts were being persistently 
eliminated. As the experiment referred to above 
shows, those with narrow fronts withstand the 
muddy water better.1. The inference was that the 
elimination was definitely discriminate. 

Prof. Bumpus’ relates an interesting observa- 
tion on the house-sparrow in North America. 
After a storm 136 were picked up and brought 
into the laboratory, where 72 revived and 64 suc- 
cumbed. Survivors and eliminated were measured 
as to length, size of wing, weight, length of head, 
length of humerus, of femur, of tibio-tarsus, width 
of head, and length of sternum. For all but the 
last of these characters the range of variation 
was considerably greater in those that succumbed, 
the extreme variants (e.g. those with longest as well 
as shortest wing-span) were eliminated (periodic 
selection). Moreover, the survivors were a little 
shorter, lighter, longer in the leg, the humerus, and 
the breast-bone. General stability of structure, Prof. 
Bumpus says, was the essential characteristic of 
the survivors. 

A fine proof of the efficacy of natural selection 


1 For criticism see J. T. Cunningham, in Nature (1898), vol. lviii. 
pp. 593-4. 

2 «The Elimination of the Unfit as Illustrated by the Introduced 
Sparrow,’ by Hermon C. Bumpus, Biol. Lect. Woods Holl, Boston 
(1898), pp. 209-26, 


202 DARWINISM AND HUMAN LIFE 


is given by Prof. H. H. Crampton’ for the Saturnid 
moth, Philosamia cynthia. A large number of pups 
were collected from a small area, and kept till they 
hatched. But only 16°6 per cent. of the total 
number collected gave perfect moths. Many of 
the pupze were dead within the cocoon (“ pupal 
elimination ’’), 129 out of 310 died in the period 
between the formation .of the imago and its 
emergence (“ pupal imaginal elimination ’’). Mr. 
Crampton compared 134 male pups that survived 
pupation with 130 that died immediately after 
pupation, as regards length, width, and depth of 
the bust of each, and as regards length and breadth 
of antenne. Those that survived were longer, 
narrower in the bust, and had longer, stouter 
antenne. Similarly, he compared 176 surviving 
female pups with 180 that died, and selection in 
type was found to be certain for all dimensions 
and to be in the same direction as in the male 
pupe. The survivors were also less variable. 
We need not discuss the pupal-imaginal elimina- 
tion, where the results were somewhat different. 
It is interesting to notice, as Mr. Crampton points 
out, that the selected characters are not such as 
seem to be directly or indirectly “useful” to 
their possessors, yet they are demonstrated to have 
the high utility of determining survival—which 
is indeed, for the evolutionist, the final criterion 
of utility.’ 

We cannot do more than allude to the careful 
statistical methods by which Prof. Karl Pearson 
and others have proved that there is selective 


1 «¢ Biometrika ” (1904), vol. ili. pp. 113-30. 
2 See “The Evidence of Natural Selection,” by E. S. Russell, 
in Rivista di Scienza (1909), vol. ii. 


SELECTION: ORGANIC AND SOCIAL 203 


death-rate in man. A certain number of people 
are killed every year in Britain by lightning; 
their death is purely fortuitous. But this cannot 
be said of phthisis, where the elimination is in part 
quite definitely discriminate. Even from the fact 
that longevity is truly heritable it is evident that 
there must be a selective death-rate in mankind. 

LESSENING THE BURDEN OF THE THEORY.— 
Another change which seems now coming about as 
the result of discussion and investigation is ex- 
pressed in a growing tendency to lessen the burden 
that has been hitherto laid—faute de mieux—on 
the shoulders of Natural Selection. We cannot 
do more than illustrate how different bodies of 
workers are arriving at the same general conclusion. 

(a) If we find increasing warrant for postulating 
the occurrence of mztatcons of considerable magni- 
tude and for believing that they are not readily 
lost when they once emerge, then it 1s not necessary 
to suppose that every character has arisen by the 
accumulation of minute steps. It goes without 
saying that mutations must pass through the 
selection sieve. 

(6) Whether we postulate mutations or fluctua- 
tions, we cannot but sympathise with the heresy 
which is often whispered, that it 1s very difficult 
to give a concrete selectionist interpretation of 
what may be called the “ big lifts’! in evolution. 


1 The difficulty in regard to “big lifts” is bound up with the 
question whether there are any qualitative steps in evolution, or 
whether change apparently qualitative may not be due to the 
accumulation of minute quantitative changes. It is said that 
there are no transitions between a sledge and a wheeled cart, and 
that a new unity cannot arise piecemeal. It is difficult, however, 
to feel confidence in these arguments from analogy. Conscience, or 
the habit of judging our actions by a standard, is a very distinctive 


204 DARWINISM AND HUMAN LIFE 


Given heritable fluctuations and selection, we can 
perhaps interpret the perfecting of an adaptive 
structure, such as an elephant’s trunk. Given 
mutations and selection and isolation, we can 
perhaps interpret the origin of a new species. 
But when we face the “ big lifts * the difficulty is 
very great. (Gymnosperms have probably evolved 
from fern-like plants. But “ the seed and all that 
goes with it is a new character, and how selection 
could have originated it is a question at whose 
answer even scientific imagination balks. It is 
evident that the ovules of Gymnosperms are related 
by descent to the sporangia of ferns in some way, 
but so extensive a change does not seem to come 
within the possibilities of natural selection.” ? 

It may be noted that some paleobotanists, 
notably Grand’EKury and Zeiller, maintain that the 
rock-record 1s distinctly suggestive of the sudden 
appearance of new forms differing by marked 
characters from those that gave them birth. 

(c) Another view which finds adherents is that 
many minor characters are the physiological or 
developmental concomitants of major characters 
which have undeniable selection-value. They 
follow in the wake of the more primary qualities. 
Thorns used to be interpreted by the eager Darwin- 
lans as a protection against grazing animals, and 
human character, and yet it is conceivable that it has evolved from 
pre-human habits by a series of very slight changes, some of the 
links being found in self-subordinating behaviour among animals, 
in parental care, in the law of the pack. As Norman Wilde puts it, 
“Because darkness passes through twilight into day by imper- 
ceptible degrees, we do not deny the difference in quality between 
darkness and light.” 

1 “The Theory of Natural Selection from the Standpoint of 


Botany,” by Prof. John M, Coulter, in “ Fifty Years of Darwinism ” 
(1909), p. 60, . 


SELECTION: ORGANIC AND SOCIAL 205 


they seem sometimes to have this value. But 
this cannot be the whole truth. Apart from the 
Just objections that thorns are often prevalent in 
countries where there are few grazing animals and 
that they do not appear in the early stages when 
they are most needed, experiment has shown that 
many thorns arise in response to poor nutrition. 
Thorns are the natural outcrops of a kind of con- 
stitution suited to dry countries. 

This idea was familiar enough to Darwin, as we 
see from the emphasis which he laid on instances 
of “correlated variability.” In this connection, 
Sir Ray Lankester observed, at the Cambridge 
Centenary Celebrations: “In my opinion he has 
thus furnished the key to the explanation of what 
are called useless specific characters and of in- 
cipient organs. That key consists in the fact that 
a general physiological property, or character of 
utility, is often selected and perpetuated which 
carries with it distinct, even remote, correlated 
growths and peculiarities obvious to our eyes, yet 


1 See Coulter, op. crf. (1909), and Geddes, ‘‘ Proc. Brit. Assoc.’’ 
(1889.) Prof. Coulter points to significant facts like the following : 
the nettle can get on quite well without its stinging hairs; many 
seeds, especially in arid regions, develop a testa so hard that it inter- 
feres with the breaking through of the embryo—which looks like 
“ over-adaptation’”’ ; further investigation has played havoc with 
the pretty story of the extra-floral nectaries attracting a body-guard 
of harmless ants. It is probable that in these and a hundred other 
cases our task is rather that of discovering the physiological and 
embryological significance of the structures in question, than that 
of searching diligently for a utilitarian justification which does 
not exist. A familiar example may be found in our finger-prints, 
which illustrate discontinuity in evolution—the apparently abrupt 
origin of new patterns; but, as we have no warrant for supposing 
that natural selection operates in any way in this case, we must 
suppose that these patterns are the expressions of internal growth- 
conditions. 


206 DARWINISM AND HUMAN LIFE 


having no functional value. At a later stage in 
the history of such a form these correlated growths 
may acquire value and become the subject of 
selection.” * 

(d) Among paleontologists, too, there are some, 
like Prof. H. F. Osborn, who make out a strong 
case for the origin of new characters by definite 
progressive variation, and “not by the selection 
of the fit from the fortuitous.’ In other words, 
many paleontologists claim that indefinite varia- 
tions off the main line are absent, so far as the 
rock-record tells. 

“The law of gradual appearance or origin of 
many new characters in definite or determinate 
directions from the very beginning [ regard as 
the grandest contribution which paleontology has 
made to evolution.”? We must attach great 
importance to this expression of opinion, for it is 
shared by many who, like Prof. Osborn, have 
given their life to studying the actual history; but 
it must be borne in mind that highly specialised 
types, like Ammonites and mammals, may be like 
well-pruned trees—they may have been selected 
through long periods into lines of determinate 
variation. The power of divergent idiosyncrasy 
may have been pruned out of them. 

After referrmg to the work of Waagen on 
Ammonites and his own work on mammals (e.g. 
their teeth), Prof. H. F. Osborn says: “ The law 
of gradual change in certain determinate, definite, 
and, at least in some cases, adaptive directions, 
through very long periods of time, and the absence 


1 Nature (July 1, 1909), p. 10. 
2 “Darwin and Paleontology,” by H. F. Osborn, in “ Fifty 
Years of Darwinism ”’ (1909). 


SELECTION: ORGANIC AND SOCIAL 207 


of chance and non-direction in the origin of a large 
number of adaptive and other new characters, is 
the common working principle both in Vertebrate 
and Invertebrate paleontology.” ! 

(ec) Another change of view—rank heresy to those 
of the straiter sect of Darwinians—is seen in the 
writings of not a few naturalists who do not feel 
themselves bound to find a use for everything. 
There are many apparently trivial characters for 
which careful investigation has discovered very 
definite and unexpected utility—Weismann gives, 
as an example, the beautiful microscopic anchors 
and discs of lime found in the skin of the burrow- 
ing, worm-like Holothurians known as Synaptids; 
but, on the other hand, the tyranny of an ex- 
treme zoological utilitarianism may become absurd. 
When the wind blows the long, sharp-pointed leaf 
of the sand-binding bent-grass it often makes a 
perfect circle on the sand, but there is no signifi- 
cance in this. Nor is there in the beautiful ripple- 
marks on the sand or in the frost-flowers in the 
window. It seems likely that there are many 
such things in living creatures—registrations of 
orderly functional rhythms, the ripple-marks of 
periodic growth. The cross barring of a feather 
may simply express diurnal variations in blood- 
pressure when the feather was developing. That 
it may come to be useful is another matter. 

SEXUAL SELEcTION.—As a corollary to his 
theory of natural selection, Darwin expounded a 
theory of sexual selection, in which he interpreted 
some of the secondary peculiarities of the sexes 
as the outcome of selective processes involved in 
the combats of rival suitors and in the choice 

1 Op. cit. (1909). 


208 DARWINISM AND HUMAN LITE 


exercised by the coy females. All sorts of mascu- 
line weapons, such as antlers; all sort of decora- 
tions, such as brilliant plumage; all sorts of 
excitants, such as love-calls and fragrance, may 
be interpreted in terms of the sexual selection 
which seems to occur in many cases, especially 
where there are more males than females, or where 
polygamy occurs. The whole matter 1s difficult, 
perhaps more difficult than Darwin thought, and 
there is great difference of opinion in regard to it. 
Wallace did not see his way to believing at all 
in the action of female choice; Weismann was 
whole-heartedly with Darwin. It must suffice to 
refer to a few of the post-Darwinian contributions 
to this fascinating subject. 

(a) The combats of rival males are often very 
fierce. ‘The younger or weaker candidates may be 
killed, or expelled, or left unmated. In such 
cases there seems little reason to doubt the dis- 
criminateness of the elimination. In some curious 
cases, as in spiders, the tournaments are prolonged, 
but the combatants do not seem to hurt one 
another; and it is possible that the significance 
of the jousting is to excite the females, who some- 
times stand by, as it were interested spectators. 
In some other cases, e.g. among Lamellicorn 
beetles and Bearded Monkeys, there seems to be 
more bluffing than fighting, for precedence is given 
to the candidate of most imposing appearance. 

(b) In regard to those masculine characters which 
indubitably attract the female and probably serve 
to excite her and to overcome her coyness, Wallace 
consistently maintained that there was very 
little clear evidence that the female chooses a 
partner out of a number of suitors. At the same 


PLATE XI 





SEx DIMORPHISM. 


The males are to the left, the females to the right. 

A and a, Male and female Hercules Beetles (Dynastes). 

B and b. Male and female spiders, Vephila nigra (atter Vinson). 

C and c. Male and female crested newts, Zriton (or Molge) cristazus. The male has 
,a scotloped dorsal median fin. 

D and d. Male and female Bird of Paradise, Paradisea apoda. 


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SELECTION: ORGANIC AND SOCIAL 209 


time, there is evidence, in some cases, that certain 
males are left out in the cold unmated, and that 
these are inferior in attractiveness or in stimulating 
power. 

(c) While the cases of preferential mating which 
Darwin relied on, for instance among birds and 
butterflies, require further study in the light of 
criticism, there is no doubt that in many cases the 
males exert themselves to display their special 
qualities. Thus Prof. and Mrs. Peckham have 
described, in spiders of the family Attide, the extra- 
ordinary dances of the males before the females. 
That the female literally chooses the handsomest 
dancer remains unproved, yet it is well known 
that she often punishes a suitor who does not 
adequately please her by killmg him there and 
then. 

(d) In many cases, e.g. the antlers of stags, 
there is a very intimate correlation between the 
reproductive organs and the development of the 
secondary sex characters. Itseems that an internal 
secretion from the reproductive organs is neces- 
sary to start the development of certain secondary 
sex characters. ‘There is also evidence that the 
secondary diflerences between males and females 
hang together physiologically, being manifold out- 
crops of the deep constitutional difference which 
makes of one animal an egg-producer and of another 
a sperm-producer. But this kind of inquiry, still 
very incipient, 1s at a level deeper than that of 
sexual selection, which does not touch the question 
of origins. 

(ec) It is now generally believed that what the 
female chooses is not so much slight improvements 
in chirping or song, slight excellences in colour 


14 


210 DARWINISM AND HUMAN LIFE 


or scent, but rather the tout-ensemble of that male 
who most excites her sexual interest. As Weis- 
mann says: “ Even though we certainly cannot 
assume that the females exercise a conscious choice 
of the ‘handsomest’ male, and deliberate, like 
judges in a court of justice, over the perfections 
of their wooers, we have no reason to doubt that 
distinctive forms (decorative feathers and colours) 
have a particularly exciting effect upon the female, 
just as certain odours have among animals of so 
many different groups, including the butterflies.” ’ 

Though Darwin sometimes seems to credit the 
female with no small degree of esthetic fastidious- 
ness, he also states that “it is not probable that 
she consciously deliberates; but she 1s most 
excited or attracted by the most beautiful, or 
melodious, or gallant males.” As Lloyd Morgan 
says: “The most vigorous, defiant, and mettle- 
some male is preferred, just because he alone affords 
a contributory stimulation adequate to evoke the 
pairing impulse, with its attendant emotional 
tone.” From the human point of view, perhaps 
the most important fact is that, in the course 
of evolution, sexual behaviour has come to be 
associated with psychological values which hitch 
it to the skies. 

IsoLation.—Besides selection in its varied forms 
there is another directive factor in evolution— 
which Darwin to some extent recognised—and 
that is Isolation. This term is used to include 
all the means which restrict the range of inter- 
crossing within a species: geographical barriers, 
such as arise when a peninsula becomes an island ; 
temporal barriers, such as arise when the members 

1 “ Darwin and Modern Science ” (1909), p. 47. 


SELECTION: ORGANIC AND SOCIAL 211 


of a species reach sexual maturity at different 
times of year; habitudinal barriers, when a species 
splits into two or more castes with different habits 
of life ; physvological barriers, such as arise by some 
variation in the reproductive organs ; and psycho- 
logical barriers, which rest on profound antipathies. 
The subject has been worked at a good deal since 
Darwin’s day, by Wagner, Gulick, Romanes, 
Jordan, and others—and Romanes went the length 
of saying that Isolation was a sine qua non in the 
origin of new species. The great difficulty is to 
get a sufficient body of reliable facts. 

From many passages in Darwin’s works it is 
evident that he recognised that isolation, or seerega- 
tion, is Important in natural selection, just as it is 
in artificial selection. “I do not doubt,” he says, 
“that isolation is of considerable importance in 
the formation of new species.” But he did not 
analyse the idea as some post-Darwinian workers 
have done. 

When a species spreads, several contingents may 
become isolated from one another, and, if different 
variations spring up in the several contingents, 
then the isolation will favour the origin of distinct 
species. It works in two ways: (1) by preventing 
intercrossing and its possibly levelling effects, and 
(2) by involving close inbreeding, which develops 
prepotency or stability of type. There is one 
bird peculiar to Britam, namely, the red grouse, 
but it is closely allied to the Scandinavian willow 
grouse, and it seems impossible to doubt that 
the literal isolation of Britain has allowed the 
red grouse to diverge as a new species from the 
willow grouse stock. | 

There are said to be eighty species of the land- 


212 DARWINISM AND HUMAN LIFE 


snail Cerion on the Bahama Islands, and Gulick 
reports 200-300 species of the land-snail Achati- 
nella in the various valleys of the Sandwich Island 
Oahu. 

President Jordan has devoted some attention 
to the occurrence of cognate or “ geminate ”’ 
species on opposite sides of some barrier. “ In 
a general way, such species agree with each other 
in all the respects which usually distinguish species 
within the genus. Their differences appear in minor 
regards, characters of degree, or proportion— 
traits which we may safely suppose to be of more 
recent origin than the ordinary characters marking 
off species within the group.” As examples of 
what are probably in some measure the results 
of isolation, he takes the followmg: “ Hach 
well-separated island in the West Indies has its 
own form of golden warbler. Hach island in the 
Kast Indies has its own forms of reptiles, monkeys, 
snails, and fresh-water fishes. Each island in 
Hawaii has its own species of each genus of 
Drepanine birds; each forest its own type of 
land-snails. Each of the three groups of rookeries 
in Bering Sea has its own species of fur-seal. 
Hach section of the Isthmus of Panama has its 
geminate species of fishes, representing nearly 
every genus or sub-genus of the shore-water off 
Mexico.” * 

There is considerable evidence to show that 
isolation, with its attendant inbreeding, has played 
an important role in human evolution, fixing and 
intensifying and giving hereditary grip to types 
which began their career in small communities. 


1 “Isolation as a Factor in Organic Evolution,” in “ Fifty 
Years of Darwinism” (1909), p. 81. 


PLATE XII 





———— 


EARLY STAGES AND LATE STAGES IN EVOLUTION-SERIES. 


A, A very early 4-toed ancestor of the horses. a. The modern horse. 
figures are in proportion. 


B. Head and skuil of an early ancestor (Merithcrium) of the elephant. b. Head and 
skull of the modern elephant. 


C. The oldest known bird, Archeopteryx, two specimens of which have been obtained 
from Jurassic strata. c. A typical modern bird—a golden eagle. 


The two 


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SELECTION: ORGANIC AND SOCIAL 213 


SELECTION IN HUMAN SOCIETY 


GRADUAL DimiInuTION oF NATURAL SELECTION 
IN Manxinp.—In early days man had probably 
a precarious foothold on the earth, contending 
with wild beasts and with physical conditions of 
which he had little mastery. The serpent bit 
his heel, the thorns cut his naked skin, the floods 
rose and drowned him in his cave. There was 
probably much squabbling around the platter of 
subsistence, a keen and literal struggle, and it 
may be that we owe much to the natural selection 
of those ancient days. But as age succeeded 
age, and man’s brain developed, he cared less 
and less for what serpent or thorn or flood could 
do; his struggle for existence changed in tone 
and colour. And nowadays, except in the out- 
skirts of civilisation, there are few wild beasts 
that worry man much, the serpent that bites 
his heel is usually more or less microscopic, 
every year increases his mastery over physical 
forces, and he is extending his kingdom to the 
heavens. 

All through the ages there has been a winnowing 
by disease and famine, still very marked in certain 
peoples, and to this also, as regards some of our 
qualities, we have probably owed much. Of the 
primeval crudity of the struggle for existence, 
to which sections of mankind are sometimes 
forced back, we get occasional appalling glimpses ; 
for instance, when a panic unmans men altogether. 
But every one knows that we do all that in us 
les to put a stop to elimination by disease and 
famine. Partly through genuine sympathy, partly 


214 DARWINISM AND HUMAN LIFE 


from a desire to avoid unpleasantness, we insist 
on keeping the unfit alive. 

As the struggle with physical forces and with 
wild beasts became easier, with more frequent 
breathing-times and with more encouragement to 
self-asserteveness, there came to be more com- 
petition between fellows, and it may be that we 
owe much to the deadly inter-tribal wars of ancient 
times, which would tend to favour not only strength 
but solidarity. Conflict still continues among 
civilised peoples, in trade as well as in war; but 
it does not correspond in any close way to the 
struggle for existence that goes on in Nature. A 
nationality is not a biological unit hike a species. 
Even in the most terrible wars nation no longer 
exterminates nation, and victory is not necessarily 
with those of the stronger or finer organic qualities. 

CONTRAST BETWEEN THE HUMAN RACE AND THE 
AntmMaL Wor tp.—It is not necessary to spend 
time in showing at length that the venue changes 
sreatly when we pass from the animal world to 
the human race. Apart from the social feelings 
which make the cruder forms of natural selection 
intolerable, there are many complicating factors. 

Animals have very little power outside their 
own constitution of strengthening their position 
in the struggle for existence, but man has much. 
He gets to himself appliances and instruments, 
engines and machines, and the dwarf bends the 
Titan to his will. Brain and its many inventions 
count in mankind for far more than body. 

Most animals have no inheritance outside of 
themselves, but in mankind there are many kinds 
of external legacies. It is only in a very literal 
sense that the millionaire’s son can say, “ Naked 


SELECTION: ORGANIC AND SOCIAL 215 


came I forth,’ and an inherited title may save 
a man in the social struggle for existence when 
neither his body nor his brains could avail. 

The notable change that has been evolved is 
the method of externally registering the gains of 
experience and to some extent also the achieve- 
ments of genius. Customs, conventions, traditions, 
language, literature, art, institutions, the whole 
framework of civilisation have put human societies 
ona different plane from that occupied by individual 
organisms. 

If a number of unsociable men were shipwrecked 
on a Robinson Crusoe island and lived each for 
himself, a more or less natural selection maght 
occur. In human societary forms, however, there 
is so much division of labour that, all social senti- 
ment apart, many get a chance whom Nature 
would not tolerate. As a simple illustration, we 
may note that the extremely short-sighted are by 
no means excluded from having a successful career. 
Even short-sighted dogs and horses survive in 
domestication. But in wild nature a short-sighted 
vulture must perish; it cannot get spectacles. 

Moreover, the increase of a human population 
can go on beyond the limit which holds for animal 
increase, namely what the environment can directly 
support. Man evades this by discovering some 
new way of getting more out of the environment, 
and he may also ingeniously adjust himself by 
changing the standard of living and introducing 
some fresh subtlety into the art of life. Man’s 
power of transforming his environment, rather 
than being transformed by it, 1s mncomparably 
greater and on much larger lines than anything of 
the kind among animals. 


216 DARWINISM AND HUMAN LIFE 


Most animals have to get their own food directly ; 
we cite as great rarities cases like that of the 
slave-keeping ants, who not only have their food 
collected but have literally to be fed by their 
minions. But in mankind the majority get their 
bread and butter in exchange for something else. 
Thus types that could not survive in open nature 
flourish bravely. 

Wherever societary forms of one kind or another 
evolved among men, integrates as distinguished 
from aggregates, each with the capacity of acting 
as a unity, the manner of evolution was pro- 
foundly changed, passing into a realm of new 
values—of a higher order than the purely bio- 
logical. This is well brought out in Keller’s 
Societal Evolution (1915). 

The same truth—so obvious and yet so persis- 
tently lost sight of—is eloquently expressed, at a 
higher level of application, in Chalmers Mitchell’s 
“ Evolution and the War” (1915), in which he 
asserts “‘as a biological fact that the moral law 
is as real and as external to man as the starry 
vault ’ above him. “It has no secure seat in 
any single man or in any single nation. It is the 
work of the blood and tears of long generations 
of men. It is not in man, inborn and innate, 
but is enshrined in his traditions, in his customs, 
in his literature and his religion. Its creation and 
sustenance are the crowning glory of man, and his 
consciousness of it puts him in a high place above 
the animal world. Men live and die; nations rise 
and fall, but the struggle of individual lives and of 
individual nations must be measured not by their 
immediate needs, but as they tend to the debase- 
ment or perfection of man’s great achievement.” 


SELECTION: ORGANIC AND SOCIAL 217 


We find in Man as an organism illustrations of 
all the categories of organic evolution—variability, 
heredity, selection, and adaptation. The same 
formal categories are illustrated when we pass 
from Man to human society, from organismal to 
societary evolution, but it is a fallacy—well exposed 
by Keller—to suppose that societary variation, 
societary transmission, societary selection, and 
societary adaptation are the same as those which 
obtain in the realm of individual organisms. 

SOME NATURAL SELECTION PERsists In Man- 
KIND.—l'o return to the main trend of our argu- 
ment, we find that much of the selection that takes 
place in human society is very different from 
natural selection, but while we systematically 
thwart the process of natural selection, some still 
persists in present operation. Let us get a hold of 
Prof. Karl Pearson’s argument. If Darwinism 
apples to man, “‘ we must have evidence (1) that 
man varies, (2) that these variations, favourable 
or unfavourable, are inherited, and (3) that they 
are selected.” (1) “The extent of variation in 
both man and woman has been measured by the 
Biometric School in nearly two hundred cases.” 
(2) “There appears no doubt that good and 
bad physique, the liability to and the immunity 
from disease, the moral characters and the mental 
temperament, are inherited in man and with 
much the same intensity.” (3) Careful work has 
shown that the death-rate in man is _ partly 
selective—a function of his constitution. But 
while there is still some natural selection left at 
work, it has diminished out of all proportion to 
the need for it. ‘‘ Consciously or unconsciously, 
we have suspended the racial purgation main- 


218 DARWINISM AND HUMAN LIFE 


tained in less developed communities by natural 
selection.” 

Sir Ray Lankester has pointed out that the 
ceaseless increase of man is absolutely peculiar 
to him of all living species, animal or vegetable, 
and this is, as Saleeby says, “ the source of the 
major facts of history and the besetting condition 
of every social problem that can be named at 
this hour.” Man’s persistent increase 1s the more 
remarkable since he is well known to be a slowly 
reproducing animal—slowest perhaps, except a 
few extreme cases like the elephant. The point 
is this, that whereas most animals have a much 
higher birth-rate than man, there is none with 
such a low death-rate. The meaning of this is 
that man has thrown off the natural selection 
bondage, and insists on saying, and saying success- 
fully, ‘‘ I will live,” when every natural chance 
is against him.! 

THe DitemMA oF Civinisation.—The whole 
trend of evolution since civilisation began has 
been to throw off the yoke of natural selection, 
and we are thus brought face to face with a for- 
midable dilemma. It is impossible to return to a 
natural selection régime, and yet we have not 
been able to put an equally effective social selection 
into operation. No one has stated the dilemma 
more clearly than Herbert Spencer: “ The law 
that each creature shall take the benefits and 
the evils of its own nature has been the law 
under which life has evolved thus far. Any 
arrangements which, in a considerable degree, 
prevent superiority from profiting by the rewards 


1 See *‘ The Kingdom of Man,” by Sir E. Ray Lankester. (London, 
1906.) 


SELECTION: ORGANIC AND SOCIAL 219 


of superiority, or shield inferiority from the 
evils it entails—any arrangements which tend to 
make it as-well to be inferior as to be superior, 
are arrangements diametrically opposed to the 
progress of organisation, and the reaching of a 
higher life.” | 

THE EXTREME “ LAIssez-FAIRE ”’ Postrton.—In 
face of this dilemma various suggestions have been 
made. ‘The first is that we should try to restrict 
our kindness—a kindness which the future may 
call cruelty. Plato, in his “‘ Laws,” recognised the 
value of the “ purgation of the State * which was 
effected automatically by a stern struggle for 
existence; and to an interference with natural 
selection, 1t is said, much of our sea of troubles is 
due. Can we not return, then, in some measure 
to the old régime? Should we not be more 
guarded in our interference with natural elimination, 
e.g. in preventing the elimination of weaklings and 
wasters whose survival and propagation cannot but 
be a drag on the race ? 

This suggestion is open to many objections. In 
the first place, there 1s the general answer that, as 
civilisation has involved continuous interference 
with natural selection, there is danger in the 
proposal to pursue directly opposite tactics. To 
let a weakling die or to help it to die might be 
justifiable biologically and yet most detrimental 
to the welfare of a human society. In the second 
place, the theoretical suggestion to return to the 
old natural selection régime is not practicable, 
partly because of the complexity of our social 
organisation, which offers so many niches of 
opportunity to weaklings and wasters, and partly 
because, without a great change in social senti- 


220 DARWINISM AND HUMAN LIFE 


ment, it is in civilised communities quite impossible 
not to try to save those to whom Nature would 
show no mercy. It is likely that we are often 
cruel in our charity, but we cannot altogether help 
it. In the third place, we do not as yet know 
enough to be sure, except in a few cases, that if 
certain members of the community are allowed 
to die the race will be physically fitter. 

Besides these general objections to the extreme 
laissez-faire position, there are many particular 
objections. Let us take, for instance, the sugges- 
tion that we should cease supporting hospitals and 
the like. ) 

(1) Our attempt to lessen an artificially ex- 
ageerated infantile mortality cannot be accurately 
described as an interference with the order of 
nature ! 

(2) Much weakness which we try to strengthen 
is only superficially, not organically weak; and 
while we keep alive some who are rotten we save 
many who only require temporary shelter. One 
enthusiast over bacterial selection says: ‘‘ The 
higher the infantile mortality which medicine so 
energetically combats, the surer is the next 
generation of being purged of all weak and sickly 
organisms.” But he forgets that the infantile 
maladies also affect the intrinsically strong and 
capable, and often weaken them, one might say, 
quite gratuitously. 

(3) Many of the microbes which thin our ranks 
are very indiscriminate: they remove the wrong 
people. Prof. Berry Haycraft, in his “ Darwinism 
and Race Progress,”’ points out that the hygienists, 
in warring against microbes, are eliminating the 
eliminators who have made our race what it is. 


SELECTION: ORGANIC AND SOCIAL 221 


This is a very doubtful thesis; but, even if it 
were true, it is open to us, as the author of 
course recognises, to put other modes of selection 
into operation. Can man not select better than 
bacteria @ 

SocraL SurGERY.—A second suggestion, which 
goes a step further than the first, 1s that we should 
take more thought for the morrow by deliberately 
pruning our stock of its diseased buds, especially 
of those who, if they survive, will be miserable 
themselves and a cause of misery to others. 

Nietzsche had the courage to say what many feel, 
that it would be a kindness to suppress a good many 
of us. There is no doubt about that, but would 
it be a permissible kindness? Who is sufficient 
for these things? It is one thing to discourage 
in every feasible way—compatible with rational 
social sentiment—the breeding of weaklings by 
weaklings ; it 1s another thing to look a fellow 
creature in the eyes and say, “ You must die.” 
Remove weaklings, forsooth! read over the roll of 
them first; might they not say, “ Yet we are 
the movers and shakers of the world for ever, it 
seems ”’ ? 

Perhaps the time may come when the noblest 
social sentiment and a maturer science will agree 
that this bud and that should not be allowed to 
open; but the time is not yet. The biologist dis- 
trusts social surgery because of his ignorance ; 
the sociologist rejects 1t because the thought of 
it makes the foundations of society tremble, and 
because the social ideal of good citizens is wider 
than the ideal of good physique ; and the practical 
man will not hear of it because he knows that 
it is not in us to practise it. Even if the way 


222 DARWINISM AND HUMAN LIFE 


were clear, it would be like destroying fruits and 
leaving roots, and securing a fictitious comfort by 
an entirely artificial method of disowning our 
social liabilities. 

Is SoctaL SELECTION COMPENSATING FOR THE 
DIMINUTION OF NATURAL SELECTION ?—A third 
suggestion leads us nearer practicable tactics, for 
it raises an inquiry into the modes of selection 
which are at present in operation in human 
societies. How do these compare with natural 
selection, and how far can they be trusted to 
effect the purgation of the State ? 

Whatever form natiral selection may take— 
and it has a thousand—this is always true about 
it, that the eliminated are eliminated because of 
some defect in or pertaining to them, “ the unlit 
lamp and the ungirt loin ’” in some form, and that 
the survivors survive because of some relatively 
advantageous quality in or pertaining to them. 
But there are many selective processes in human 
society which depend on something else than the 
inherent bodily or mental quality of those selected. 
Let us consider some illustrations of these. 

A German Professor, writing of the enormous 
mortality of children in large towns, says that all 
those young lives must pass out because there is 
no place laid for them at Nature’s great table: 
“Natural selection, don’t you know.” But the 
hideous mortality in question has almost nothing 
to do with Nature’s great table or with natural 
selection. Howcan one tell? The statistics show, 
to some extent, what the children die of, and it 
is, to a large extent, of their parents! For some 
large towns the deaths of infants have been care- 
fully classified, not only as to the cause of death, 


SELECTION: ORGANIC AND SOCIAL 223 


but in reference to what the parents do or do not 
do; the mortality is double in some classes what it 
is in others; and this seems certain, that in many 
cases the selection is not related to the physique 
of those eliminated. The selection depends, in 
great part, on the parental standard of comfort and 
standard of character. 

But, it may be said, if there is a differential death- 
rate, a larger infant-mortality in the less thrifty 
families, will that not work out right in the long 
run, since their elimination implies a sifting out of 
the hereditarily thriftless types? The answer is 
that, along with the greater mortality, there is 
associated a greater fecundity, so that the sifting 
is partially counteracted ; moreover, it is not to 
be supposed that the less thrifty families with high 
infant mortality are to be thought of as necessarily 
undesirables; much of the thriftlessness is as 
artificial as much of the mortality is unnecessary. 

Take another instance, which may serve to bring 
out the difference in method and results between 
social selection and natural selection. In some 
countries there are posts as foresters and police 
which are filled by picked men, often by very 
desirable types physically, mentally, and morally. 
Tiere, then, is the setting up of a standard and a 
rejection of the unfit; and, of course, it works in 
the right direction. But it is easy to see that it 
differs from what goes on in nature, and that the 
issues are complicated. For instance, as a German 
writer points out, the ineligible were also meligible 
for military service. ‘This means that they are 
spared time and money, that they can marry 
earlier, and that they can continue their kind. 

The stress of competition exercises a certain 


224 DARWINISM AND HUMAN LIFE 


selective influence, but how differently it works 
from natural selection! It does not necessarily 
make for the elimination of the unsuccessful ; it 
shifts him. It may compel him into an occupation 
where his chances of death are lessened. If he is 
driven out of regular employment altogether, he 
passes into ranks with a high death-rate, but even 
then natural selection does not work, for he usually 
has a large family in the meantime. Thus we see 
that many processes of differential elimination in 
human societies turn out, on close inspection, to 
be very different from natural selection, and this 
is our whole point at present—that these processes 
of social selection cannot be trusted, and that 
nothing is more absurd than to murmur “ Survival 
of the fittest ’’—since that is precisely what is not 
happening either in the Darwinian sense or in any 
other. 

REVERSED SELECTION IN HUMAN SOCIETY.— 
Those who are unfamiliar with the biological point 
of view seem to find it difficult to bear in mind 
that organisms may evolve “ downwards ”’ as well 
as “upwards” in becoming fitter to given con- 
ditions. By “upwards” is meant in the direction 
of a more differentiated and integrated organisa- 
tion—a more complex and controlled constitu- 
tion—and we have a habit of regarding ourselves 
as being very much “up.”’ Now, while it is true 
that the general trend of evolution throughout 
the ages has been “ upwards,”’ we must not forget 
that the tapeworm has been evolved as truly as 
the golden eagle, the one in a dark bypath, the 
other on the mountain-tops, both well adapted 
to their conditions of life. 

The term “ reversed selection ’’ has been applied 


SELECTION: ORGANIC AND SOCIAL 225 


to cases where, under altered conditions, organisms 
seem to have gone “ downwards,” but the term is 
unfortunate. If by selection a race is becoming 
better adapted to the conditions of its life, it is 
to the cold-blooded scientific onlooker immaterial 
whether the direction of the race-movement is 
up or down. It is evolution all the same. Con- 
sidering the movement in relation to a standard, 
however, we may say that some selective processes 
make for progress along the lines which have 
marked the general trend of evolution—greater 
complexity, greater control, a fuller, freer life— 
and that other selective processes make for change 
in the opposite direction. 

Our question now is, are there in human 
society selective processes at work which make 
for degeneracy ? We all know the difficulty of 
answering this question, because social processes 
are so complex and many-sided. Even when 
the social selection 1s in part wrong we cannot 
always stop it. Civilisation 1s a long-drawn-out 
compromise. 

In illustration, let us briefly consider the bio- 
logical aspect of prolonged wars. In his “* Human 
Harvest ’ President Jordan tells of a man more 
strenuous than wise, who possessed a stud of 
horses, which he would make more strong and fleet. 
“So he rode them swiftly with all his might, 
day and night, always on the course, always 
pushed to the utmost, leaving only the dull and 
sluggish to remain in the stalls. For it was his 
dream to fill these horses with the spirit of action, 
with the glory of swift motion, that this glory 
might be carried on and on to the last generation 
of horses. There were some who could not keep 


15 


226 DARWINISM AND HUMAN LIFE 


the pace, and to these, and these alone, he assigned 
the burden of bearing colts. And the feeble and 
broken, the dull of wit, the coarse of limb, became 
each year the mothers of the colts... . For a 
time whip and spur made good the lack of native 
movement . . .; but the current of life ran steadily 
downward. Hach generation yielded weaker colts, 
rougher, duller, clumsier colts, and no amount of 
training or lash or spur made any permanent 
difference for the better. The horse-harvest was 
bad. Thoroughbred and race-horse gave place 
to common beasts, for in the removal of the noble 
the ignoble always finds its opportunity. It is 
always the horse that remains which determines 
the future of the stud. In lke fashion, from the 
man who is left flows the current of human history.” 

Let us observe how Jordan works out his thesis 
in relation to men. “In the conquests of Rome, 
Vir, the real man, went forth to battle and to the 
work of foreign invasion ; Homo, the human being, 
remained in the farm and the workshop and begat 
the new generation.” Prof. Seeck, one of the 
historians of the downfall of the ancient world, 
says that it was due mainly to “ the rooting out of 
the best.” “ Only cowards remained, and from 
their brood came forward the new generations.” 
“Wars are not paid for in war times,” Franklin 
said; “‘the bill comes later.” “‘ The Roman 
Empire,” says Seeley, “ perished for want of men.” 
There were plenty of people— people with too 
much guano in their composition,’ as Emerson 
said; but even Julius Cesar noted that men were 
becoming terribly scarce. Prof. Bury writes : “‘ The 
effect of the wars was that the ranks of the small 
farmers were decimated, while the number of 


SELECTION: ORGANIC AND SOCIAL 227 


slaves who did not serve in the army multiplied.” 
The German historian goes on: “‘ Out of every 
hundred thousand strong men, eighty thousand 
were slain. Out of every hundred thousand 
weaklings, ninety to ninety-five thousand were 
left to survive.” 

But all that was long ago. So we take up 
Jordan’s ““ Human Harvest” again, and turn to 
France—to France, ever young and splendid in 
spirit. But the birth-rate continues steadily to 
fall; the average stature is lower by two inches 
than it was a century ago; and, as with ourselves, 
there are other disquieting symptoms. These are 
doubtless due to a variety of co-operating causes, 
but can we exclude what one of themselves has 
said, that ‘it will take long periods of peace and 
plenty before France can recover the tall statures 
mowed down in the wars of the republic and the 
first empire ”’ ? 

Year after year Napoleon seized the youth of 
good stature, and left their bones in great heaps 
throughout Europe. “‘ You can always fill the 
places of soldiers,’ he said; but he had eventually 
to be content with boys. “The mighty swirl of 
the Moscow campaign sucked in 150,000 lads of 
under twenty years of age into the devouring 
vortex ’’; out of 600,000 who crossed the Niemen 
to conquer Russia, 20,000 famished, frost-bitten 
spectres staggered back. It was the rapid suc- 
cession of skimmings that told. “In less than 
half a year after the loss of half a million men a 
new army, nearly as numerous, was forthcoming 
and the grim roll-call of wasted men, many of 
them wasted heroes—about half of whom were 
French—amounted, according to some, to three 


228 DARWINISM AND HUMAN LIFE 


millions.” It is true that glorious France survived 
all this bleeding, but how impoverished, qualita- 
tively as well as quantitatively ! and even a great 
life-saver like Pasteur could not restore the cubit 
of stature which the great life-destroyer had 
lopped off.? 

We admit that wars have been necessary and 
righteous—especially necessary—and that they 
may be so still, but this opinion does not affect the 
fact that prolonged war in which a nation takes 
part is bound to impoverish the breed, since the 
character of the breed always depends on the men 
who are left. How elSe can we understand what 
has happened so often, that an older civilisation 
is overthrown by another less evolved? The only 
thing a nation dies of is lack of men. 

Without carefully collected and _ carefully 
criticised statistics it is impossible to make precise 
statements in regard to the biological effect that a 
great war may have on a race, but there are more 
than hints of the dysgenic tendencies of modern 
warfare. In ancient days a battle was probably 
in many cases a sifting out of the less strong, the 
less nimble, the less courageous on both sides, and 
the result of a war or raid was probably, in some 
cases, the practical elimination of the weaker of 
two clans. In both these ways there may have 


1 While I plead guilty to disbelief in the biological value of 
modern war, I do not think this is inconsistent with an appreciation 
of the soldier’s qualities. Who does not admire what Mr. Sandeman 
describes in his ‘“ Uncle Gregory ” ? (1909)... ‘‘ That quite un- 
mistakable note that you get in a very few people who, in one way 
or another, have actually accepted death, and are only, so to speak, 
alive in the meantime. It belongs to the flawless perfection of the 
military spirit, with its entire detachment from life itself, from self- 
will, from fear, and from ease, and from all pretences,” 


SELECTION: ORGANIC AND SOCIAL 229 


been a eugenic selection of the types best suited 
for times when fighting was the order of the day. 
But times have changed and war with them. 
Nation no longer exterminates nation, and victory 
is not necessarily with those of better physique. 
Moreover among the combatants on both sides the 
elimination is often either indiscriminate, as when 
a battleship goes down, or in the wrong direction. 
There is preliminary sifting of those who go to the 
front and of those who are placed in the fighting 
line. The finest companies are set to the most 
hazardous tasks, where the mortality is often 
terrible, and the conspicuously brave are par- 
ticularly liable to be killed. The point need not 
be laboured: what Darwin said of even ancient 
times is true to-day : ‘‘ The bravest men, who were 
always willing to come to the front in war, and who 
freely risked their lives for others, would on an 
average perish in larger numbers than other men.” 

Our suspicion that war has a dysgenic influence 
grows when we think of countries with a voluntary 
system of military service, which we believe to be 
socially soundest, though a source of immediate 
weakness biologically. In the making of our 
armies there is a process of discriminate selection 
which works in the wrong way from the eugenic 
point of view. The call of their country attracts 
a larger proportion of the more chivalrous, the 
more virile, the more courageous. A nation work- 
ing on the voluntary system, and justly proud of 
it, has to face the fact that it sends to the battle- 
fields large numbers of the best of its sons, whose 
early death must mean an impoverishment of the 
race. They do not all come home. 

It is so important to avoid exaggeration that one 


230 DARWINISM AND HUMAN LIFE 


wishes to hear the other side. It is pointed out 
quite justly that a large nucleus of genuinely brave 
men must stay at home to keep things going, and 
that they form a eugenic bulwark. ‘This is true, 
but after gratefully allowing for these, we cannot 
shut our eyes to the large body of men of military 
age who cannot fight or who will not fight, whose 
ranks, therefore, will not be thinned as those of the 
combatants are. 

It is said again that elimination is confined 
to the men, so that the women remain, as they 
usually are, a eugenic safeguard. But they cannot 
directly act in this way unless they have children, 
and war tends to increase the disharmony already 
involved in many countries in the unwholesomely 
large number of unmarried women. Moreover, 
severe and protracted war tends to lower physical 
vigour throughout wide circles of non-combatants ; 
the maternal depression, like that mduced by 
famine, tends to result in arrests of development 
and in the production of under-average types. 
We have no facts to demonstrate that the germ- 
plasm is specifically affected, yet it 1s quite con- 
ceivable that very unfavourable nurtural conditions 
may induce prejudicial germinal variations of a 
heritable sort. 

It is often said that many join the fighting ranks 
simply in a desire for adventure. This is very 
difficult to prove, but even if it be true, what then ? 
The adventurous spirit is no bad thing, often im- 
plying, for instance, a healthy-minded lack of pre- 
occupation with one’s precious self. But it may 
be granted at once that not all who are killed are 
the pick of any race, or nationality, albeit they may 
be nobler in their death than many whose safety 


SELECTION: ORGANIC AND SOCIAL 231 


they secure will ever be in their life, but is there 
any getting past the fact, especially in regard to 
nations with a voluntary military service, that a 
severe and prolonged war exposes to abnormally 
great risks enormous bodies of men to whose com- 
position there has gone a high proportion of the 
adventurous, the chivalrous, the virile, and the 
simply brave? The numbers must be borne in 
mind. When many brave unmarried soldiers are 
killed, we are justified in saying that the natural 
inheritance of the country is the poorer through 
the loss of many who should have enriched the 
next generation by more than their example. Yet 
this might mean relatively little to the stock if the 
proportion of combatants to non-combatants was 
small. But if a country such as Britain has about 
6,250,000 men between 18 and 45, 13:8 of the total 
population, and out of that an army of three 
millions, this means almost every second man 
between 18 and 45. Even if it were every second 
man by lot, the thinning might only involve a 
terrible mortality, but if the fitter join the army 
in larger numbers and are thinned in larger pro- 
portions, war must be regarded as a dysgenic 
eliminator. 

It is said that military training has such marked 
beneficial effects that it counterbalances many 
losses and disablements, and no one would deny 
the value of the drill, the discipline, the plain food, 
the regular hours and all that. But in the realm of 
life we cannot make simple equations of this sort ; 
non-transmissible modifications cannot be pitted 
against innate qualities. Even if all the modifica- 
tions acquired in the training period were to the 
good, which they are not, they do not lessen the loss 


232 DARWINISM AND HUMAN LIFE 


to the natural inheritance of the race likely to be 
involved in the severe thinning of a great army. 
There is another way in which the war is likely 
to have a dysgenic influence—by handicapping the 
more individuated. Many of the combatants never 
return; many are maimed and many enfeebled 
(in spite of the remarkably increased control of 
disease) ; but most, perhaps, come safely home. 
It is too much to expect, however, that they will 
find things as they left them. With the best will 
in the world things cannot be as they were before. 
Hundreds of millions will have been spent un- 
productively and there will be need for many 
economies. This will select in the wrong direction, 
preventing marriage and so forth, for it will most 
affect the highly skilled whose work is of a kind 
that can be more or less readily dispensed with. 
Kugenics and war—the clash between ideals 
and things as they are, 1s, perhaps, nowhere more 
terrible than here. For eugenics makes for the 
maintenance and improvement of the hereditary 
good qualities of a race, while severe and protracted 
war makes for their impoverishment. There is 
rough sifting, and the meshes of the sieve are not 
eugenically determined. How far the impoVerish- 
ment will go in any case cannot be determined by 
any a proore generalisation, but must be discovered 
by statistical analysis ; how far it can be biologically 
counteracted depends upon eugenic effort and 
instinct, and what pluses there are to set against 
the minuses is a question for careful consideration, 
but some degree of impoverishment is certain. 
We are reminded, however, that the race does 
not live by the germ-plasm alone and that war 
with its terrible sifting may be worth all it costs, 


SELECTION: ORGANIC AND SOCIAL 233 


But who can predict of any war what all its cost 
may be? In his famous essay on “The Moral 
Hiquivalent of War,’ William James said elo- 
quently: “‘ Those ancestors, those efforts, those 
memories and legends, are the most ideal part of 
what we now own, a sacred, spiritual possession, 
worth more than all the blood poured out.” Per- 
haps it is so, especially if victory 1s thrown in ! 

Kivery one will agree that there are worse things 
than war—such as slavery, rottenness, softness, 
and dishonour; they are worse even than extinc- 
tion. Let us admit that war may help “ to pre- 
serve our ideals of hardihood,” “ to protect human 
nature against its weaker and more cowardly self,” 
“to keep heroism and the martial virtues alive,” 
and even to re-impress us with the imperativeness of 
eugenics, but in these concessions let us not forget 
that there are tasks of peace capable of evoking 
and disciplining an equal hardihood and heroism. 

The story of the exploration and exploitation 
of land and sea is full of records of heroes, whose 
work was constructive, not destructive. The man 
who has grit enough to bring about the afforestation 
of a country is not less worthy of honour than its 
conqueror! And of the courage of physicians and 
hygienists, administrators and reformers, there is 
no need to speak. 

It is admitted, at once, that socially regarded a 
just and honourable war may bring a compensating 
reward, especially if the right side wins, but this 
must not lead us to seek to conceal the fact that 
war, brologically regarded, means wastage and a 
reversal of eugenic or rational selection, since it 
prunes off a disproportionately large number of 
those whom the race can least afford to lose, 


234 DARWINISM AND HUMAN LIFE 


Let us sum up. (1) In our study of the Struggle 
for Existence, we emphasised Darwin’s clearly ex- 
pressed recognition of the fact that this includes 
much more than internecine competition between 
nearly related kin. It is a technical phrase to 
include all the forms of thrust and parry and 
endeavour that living creatures make against en- 
vironing difficulties and limitations. 

(2) If man insists on appealing to Nature for 
justification of his methods, he must not suppose 
that he is shut up to an imitation of that particular 
mode of the struggle for existence which may be 
called internecine conflict. There are many other 
modes, e.g. of mutual aid and increased co-operative 
integration, which are well worth trying, which, 
indeed, man has never ceased to try. 

(3) In the preceding discussion we have tried to 
show that a serious sustained international war, 
considered biologically, implies an impoverish- 
ment of the race, especially because it tends to 
eliminate a disproportionate number of these 
whom the nation can least afford to lose. ‘There is 
not in biological analogy any warrant for supposing 
that the result of war must be a survival of the 
fittest in any desirable sense. 

(4) Then again we have indicated that human 
society 1s so different from the rest of the realm 
of life—allowing of course that animal societies 
present interesting analogies—that there is apt to 
be fallaciousness in comparing modern warfare with 
anything that goesonin Nature. In his vivid book 
“ Evolution and the War” (1915), Dr. Chalmers 
Mitchell has made this point particularly clear. 

(5) Supposing, however, that a comparison be- 
tween modern human warfare and what takes 


SELECTION: ORGANIC AND SOCIAL 235 


place in nature is insisted’ on, we must clearly 
understand that its analogue (if useful analogy be 
for the sake of argument admitted) is to be found 
in the most primitive and crude form of the struggle 
for existence, e.g. when black rat and brown rat 
fight to the death (it 1s said) in a cage ; when locust 
turns on locust in a starving swarm; when the 
cannibalistic whelk larve eat their brothers and 
sisters in their cradle. Socially regarded, a righteous 
war may be at once an expression and a discipline 
of many and high virtues in combatants and 
non-combatants alike ; biologically regarded it is a 
reversion to the crudest-mode of the struggle for 
existence. 

The reason for pressing home this unpalatable 
fact, from which we see no escape, is that the rever- 
sion brings with it terrible risks of slipping down 
the steep ladder of evolution. In the actual en- 
vironment of war the decent garments of humanity 
are often torn off and more or less of the Berserk 
discovered ; and for non-combatants there is also, 
and less excusably, a tendency to reversion because 
of the necessary pre-occupation with a struggle, 
which, though iJumined with the finest heroism 
and raised to a high level by triumphs of organisa- 
tion and cheerfulness, science and strategy, involves 
a recrudescence of primitive passion. ‘the solemn 
biological and psychological fact, that the past 
lives on in our present, implies the risk of “‘ Rever- 
sion ever dragging Evolution in the mud.” What 
sowings of dragons’ teeth there must be in every 
war ; is it weakness to be afraid lest, by and by, in 
the crop that springs from them, there be some- 
thing worse than armed men ? 

PRACTICAL CONSIDERATIONS.—As_ Britain well 


236 DARWINISM AND HUMAN LIFE 


knows, it may become impossible to ensue peace 
and at the same time keep honour. All considera- 
tions of what is biologically best are swept to the 
winds before moral necessity. It does not follow, 
however, that the biological discussion is futile, 
for it may suggest some practical action. 

If a war sifts out from the possible parent-stock 
of the future a larger proportion of those who are 
relatively more fit from an evolutionary or eugenic 
point of view, what is possible in the way of counter- 
active? Among the revaluations after a great war 
may we not expect some change of public senti- 
ment in regard to eugenic ideals, some more marked 
disapproval of selfish forms of celibacy, some more 
cordial encouragement of those desirable people 
who marry chivalrously while it is still springtime 
with them, without waiting till the bridegroom has 
secured twice the income his father had? There 
is patriotism in dying for our country ; there is a 
conceivable patriotism in marrying for her and in 
bearing children for her. 

In looking for counteractives, more serious and 
widespread attention must be directed to the falling 
birth-rate and the risks involved. The facts and 
causes of the decline in the birth-rate must be 
discussed, and likewise the possibilities of checking 
the decline differentially. There is need for more 
plasticity in the ideal of “ getting on,” but it can 
hardly be regarded as a bad sign that there appears 
to be continual increase in the number of parents 
of good type who keep their families small because 
they do not wish their children—especially the girls 
—to run the risk of thwarted and unhappy lives. 
These risks have to be lessened, and that without 
making slackness feasible. In another connection 


SELECTION: ORGANIC AND SOCIAL 237 


a counteractive must be found in a continued 
lowering of the still far too high death-rate among 
healthy infants. 

As to the marriage of recruits, other than bio- 
logical considerations must be borne in mind, but 
the general eugenic position should be one of ap- 
proval, if the ages are suitable, if the records are 
good, and if there is a certainty of adequate state- 
provision for the possible widows and children— 
three large “ ifs,” 1 will be noticed. 

If the wastage of war is brought vividly home to 
men by dramatic tragedies and irreparable losses, 
it may be that they will be led to consider with in- 
creased seriousness and discernment other forms 
of vital wastage to which a nation tends to become 
blunted by familiarity. It should be interesting to 
inquire whether some of these, such as tuberculosis 
and alcoholism, are not, in part at least, dysgenic 
in their sifting. 

Galton hoped that in course of time eugenic 
principles would come to be dominant motives in a 
nation, but this is still far off. It is our duty there- 
fore to scan with careful criticism all practical 
proposals that may be hurriedly projected to meet 
crises of war strain. One instance may suffice. 

Kugenists should resist in themselves, and in all 
their organisations, the natural desire to economise 
in noble luxuries—in pictures and music, books 
and lectures, theatres and higher education. By 
all means let our criticism of consumption be in- 
tensified, but let it be enlightened. Let us prune 
our comforts before we pinch our souls. For, in 
plain words, our economising on the nobler luxuries 
means hardship and celibacy to those finer spirits 
who are the salt of the earth, whose virtue all must 


238 DARWINISM AND HUMAN LIFE 


wish to see conserved in the natural inheritance of 
the race. 

Without losing hold of the true idea and ideal of 
the state as a body politic—an organism—in which 
all have their function, from cabinet ministers to 
road-menders, we cannot suppose that all are 
equally irreplaceable. Indeed, the eye cannot say 
unto the hand, I have no need of thee, nor again, 
the head to the feet, | have no need of you; but 
it will be agreed that true artists, for instance, are 
among the higher, less readily replaceable members 
of the community. There is no risk for us of there 
being too many of them. But there is great risk 
for them of there being too few of us to keep them 
and their art alive. The enforced economies of 
war imply lopping off super-necessaries ; the danger 
is of crippling super-men. What has been said of 
artists applies also to the professions generally. 

Those who have really learned the eugenic 
lesson are those who appreciate the organismal 
factor in evolution, who recognise the fundamental 
importance of the natural inheritance, bred in the 
bone. To those of this outlook it seldom seems 
promiseful to try to change by coercion what is 
intrinsic in the creature. The hopeful line is to 
make the most and best of what we have, without 
tampering with that maimspring of life which is 
freedom. And this is a principle that must be 
upheld in the readjustments after war, when 
attempts are apt to be made to rush schemes which 
are non-eugenic in the sense of being coercive and 
incongruent with our racial temperament. 

If a man does not demand our coat, we may 
perhaps give him our cloak ; if he does not seek to 
compel us to go a mile, we may go twain without a 


SELECTION : ORGANIC AND SOCIAL 239 


srumble. The free and plastic organism, within 
reasonable limits, may be fitter than the most 
efficient product of coercive discipline, and how 
much happier ! 

We have taken war ' as a particular case of sifting 
or selection, and we have stated what appears to 
us to be the sound biological position. But in 
discussing human affairs we should never pass from 
a biological or eugenic outlook without remembering 
that itis partial. In building a wall the mason uses 
plumb-line, level, and square, and so we have to 
employ other criteria besides that of the conserva- 
tion and evolution of life. As eugenists we are 
concerned with the natural inheritance and its 
nurture, which are fundamental; as men we are also 
concerned with our social heritage, whichissupreme. 
The social organisations and institutions in whose 
life we share, the traditions of honour, veracity 
and justice, the treasures of literature and art, 
memories which ever beckon us to follow after 
valour and understanding—these and much more 
form our social heritage, to be wrought for and 
fought for as keenly as the embodied health of the 
race. Even if the natural mheritance of a race 
sufier impoverishment through the tragic shifting 
of war, there may be some national—if no per- 
sonal—compensation in the enrichment of the 
social heritage. 

SUMMARY OF THE GENERAL ARGUMENT IN RE- 
GARD TO HuMAN SELEcTION.—Turning from the 
particular case of war, let us sum up the general 
argument in regard to the operation of selective 
processes in human society. In early days there 


1 Forcing itself on our attention with tragic insistence at the 
time of revising these lectures, 


240 DARWINISM AND HUMAN LIFE 


was a keen struggle for existence with the forces of 
nature, with wild beasts, and between fellow-men. 
There was much natural selection. Gradually the 
venue changed, there has been a persistent emanci- 
pation from the yoke of natural selection, and 
among civilised peoples it has now but little sway. 
This exposes our race to the gravest risks of retro- 
gression. To obviate this, some suggest that we 
should return in part to the old régime; others 
advise the practice of some social surgery; but 
neither of these suggestions is feasible—for general 
tactics at least. It is also suggested that there 
are many forms of «social selection in operation 
which take the place of natural selection; but 
inquiry—here very superficial—shows that these 
forms of social selection do not work out as 
natural selection does, and that some of them have 
results which are, from the biological poimt of 
view, retrogressive. 

CoNSTRUCTIVE SucGEstTions.—As we are here 
mainly concerned with getting the biology of the 
problem clear, we cannot do more than hint at 
the general policy of betterment. In general, 
it cannot be other than this—to adhere to and 
increase those forms of selection which make for 
the survival of beautiful and healthful surround- 
ings, educative and wholesome occupations, sane 
and progressive men and women. ‘The first ideal 
has been called that of Eutopias, the second that 
of Kutechnics, the third that of Eugenics... They 
obviously correspond to the three fundamental 
categories of biology: Environment, Function, 
and Organism. 


1 The first two by Prof. Patrick Geddes, the third by Sir Francis 
Galton. 


SELECTION : ORGANIC AND SOCIAL 241 


SELECTION OF Kutopras.—Possessed by certain 
enthusiasms or illusions, a man may gladly live— 
and perhaps more gladly die—on a cinder-heap ; 
and there is a local patriotism which throws a 
halo round any home. But deep down in every 
healthy human being, rooted perhaps in a once 
closer contact with nature, there is a love of the 
fresh air, the clean earth, the running brook, the 
waving trees, the singing birds—a beautiful place, 
in short, such as even a garden city might afford. 

The biological importance of living in beautiful 
surroundings is inestimable. It makes for health 
of body and brain; it awakens long-dormant buds; 
it fills up the life with wholesome delights; it 
produces pleasant modifications on the individual ; 
and who can tell how its potent messages may travel 
by “ the wireless telegraphy of ante-natal life ’”’ ? 

All this is familiar, yet are we not slow to adopt 
a resolute policy of securing one of the really good 
things in life—a Eutopia? Every one knows that 
this is no Utopia, if we can only make up our 
minds to live more in the present and less in the 
future. 

SELECTION OF HEALTHFUL OccuPATIONS.—With- 
in the hands of all men of good-will there is 
a powerful instrument of progress, technically 
known as “ the criticism of consumption.” It is 
one of the most effective factors in amelioration, 
especially as regards the selection of healthful 
occupations. Perhaps more might be made of it 
if the strategy involved was more generally recog- 
nised. When we discover that certain articles 
are socially injurious, bad for the maker, bad for 
the buyer, we should not buy them, but get instead 
something which it was good for a man to make, 


16 


242 DARWINISM AND HUMAN LIFE 


and good for us to have. Now, if we do this 
consistently and keep at if unwaveringly, and 
get others to do the same, we will, if we keep 
the selection a-going long enough, often enough, 
stringently enough, put an end to an ugly article 
and an injurious occupation. ‘The process is never 
quick enough to be unjust or cruel, as the swings 
of fashion often are. Apply this consistent selec- 
tion to favouring wholesome people, not wasters, 
constructive occupations, not destructive ones, 
beautiful places, not ugly ones—and we have 
returned to Nature’s method on a higher turn of 
the spiral. Even natural selection would favour 
the survival of qualities like healthfulness ; it is 
for a rational social selection to continue the 
endless task. 

Kucenic SeLection.—The third aspect of the 
biological ideal towards which it is necessary to 
select is the improvement of the human breed— 
the ideal of eugenics. There is perhaps no nobler 
enthusiasm, and while some of the enthusiasts are 
occasionally carried away by their zeal, we must 
not reject the quiet wisdom of a veteran general 
like Sir Francis Galton, because of the extravagant 
utterances of subalterns. And, apart from subal- 
terns, it is not easy for even expert students pos- 
sessed by a worthy enthusiasm to keep the complex 
issues in perspective. 

Let us recall some of the facts which bring the 
importance of the eugenic ideal home to us. One- 
quarter of the married people of this country, 
one-sixth to one-eighth of the total adult popula- 
tion, Prof. Karl Pearson tells us, produce 50 per 
cent. of the next generation. “ How essential it 
is for the maintenance of a physically and mentally 


SELECTION: ORGANIC AND SOCIAL 243 


fit race that this one-sixth to one-eighth of our 
population should be drawn from the best, not the 
worst stocks!” ‘We cannot recruit the nation 
from its inferior stocks without deteriorating our 
national character.” This is the argument which 
Pearson so powerfully develops. It should be 
noted that the striking figures quoted above are 
not to be taken in any fatalistic way. By taking 
thought and courage it should be relatively easy 
to alter them. 

The statistics of diminishing birth-rate require 
careful treatment by experts. In some respects 
they admit of hopeful interpretation, for they 
point to greater forethought and restraint and to 
an improvement in the position of women, but 
the ominous fact 1s that the diminution seems to 
be differential. Further inquiry is urgently re- 
quired, but there is considerable evidence that the 
diminution tends to be greatest where it is least 
wanted, among the workers of the community and 
among the more far-seeing and provident classes. 
French statistics show that the birth-rate is less 
in proportion to the standard of comfort. At 
present the birth-rate in France is said to be 
below the death-rate in all sections except manu- 
facturing centres. Among academically educated 
Americans the average number of offspring is less 
than two. , 

There seems no doubt as to the ominously rapid 
multiplication of the relatively unfit. “‘ Degener- 
ate stocks under present social conditions are not 
short-lived ; they live to have more than the normal 
size of family.”” They have at present a better 
chance to survive and multiply than ever before. 
Especially in Britain do the weeds spread quicker 


244 DARWINISM AND HUMAN LIFE 


than the flowers. The feeble-minded are prolific ; 
certain kinds of degenerates are prolific; the 
thriftless are prolific. From a study of 150 de- 
generate families, Dr. Tredgold found that the 
average number of children in a family was 7:3, 
not including those still-born, instead of the normal 
average of four. 

Let us be as generous as we can. An unpro- 
mising bud may burst into a fine flower: John 
Bunyan’s father was a tinker. But every one is 
agreed that there should be no breeding from 
epileptics, lunatics, paralytics; should not this 
list be added to?? Is it not a pity, for instance, 
that we should look with favour on the marriage 
of deaf-mutes? Let us admit that many of the 
unfit may be only modificationally unfit—ill- 


1 In his Robert Boyle Lecture on ‘‘ The Scope and Importance 
to the State of the Science of National Eugenics ” (2nd ed., 1909) 
Prof. Karl Pearson says: “If we realise the antinomy which 
Eugenics brings to our notice between high civilisation and racial 
purgation, we ask: How can the dominant fertility of the fitter 
social stocks be maintained when natural selection has been gus- 
pended ? I do not think any wise man would be prepared with a 
full answer to this question to-day. ‘There is no sovereign remedy 
for degeneracy. Every method is curative which tends to decrease 
the fertility of the unfit and to emphasise that of the fit. We may 
find it difficult to define the socially fit, although physique and 
ability will carry us far ; but when we turn to the habitual criminal, 
the professional tramp, the tuberculous, the insane, the mentally 
defective, the alcoholic, the diseased from birth or from excess, 
there can be little doubt of their social unfitness. Here every 
remedy which tends to separate them from the community, every 
segregation which reduces their chances of parentage, is worthy of 
consideration. . . . Is not something more to be insisted upon with 
regard to the increase of good stock ?... A clean body, a sound 
if slow mind, a vigorous and healthy stock, a numerous progeny— 
these factors were largely representative of the typical Englishman 
of the past ; and we see to-day that one and all these characteristics 
can be defended on scientific grounds; they are the essentials of an 
imperial race,” 


SELECTION: ORGANIC AND SOCIAL 245 


nourished plants in the crowded garden—requiring 
only new soil. Many criminals are simply ana- 
chronisms—people out of time and out of place— 
who need, not incarceration, but transplantation. 
Cure the poacher by making him a collector. But 
this will not cover all. 

Let us admit, too, that very bad stock—such 
as the uncontrolled alcoholic type—tends to work 
itself out. Taints may be swamped, just as ex- 
cellences often are. 

Prof. Biffen has bred into a good stock of 
corn the quality of immunity to rust which a 
poor stock had, and perhaps—perhaps—the 
future has in store for us analogous ways of 
getting a clean thing out of an unclean in human 
kind. 

Meanwhile, what is to be done? Many gentle 
measures are possible—fostering pride of race, 
encouraging the marriage of desirables, developing 
prejudice against the marriage of undesirables, 
fuller recognition of woman’s rights, both as to 
mating and maternity. For another step we shall 
soon be ready—a form of rational social selection 
—the institution of a sort of marriage test and some 
attempt to prevent the multiplication of those who, 
by their own inefficiency, have fallen back on the 
community for support. 

Whymper, in his “ Scrambles among the Alps,” 
says some forcible things about the marriage—the 
Church marriage—of cretins who once swarmed 
in the valley of Aosta and elsewhere. For many 
generations the strongest and healthiest peasants 
had to go to the wars ; the idiotic and goitrous were 
left. The disease may not be in itself hereditary, 
but susceptibility to it is; and in one village it 


246 DARWINISM AND HUMAN LIFE 


was said that all had a goitre except the young 
priest. In any case the cretins of Aosta throve 
and multiplied, and the consummation of the 
tragedy was when the Church solemnised their 
union. At one end we have the celibacy of the 
clergy—often remarkably fine peasant thinkers 
and dreamers—and the celibacy of the most gentle 
and spiritual women—a segregation from the race 
of some of its finest types—at the other end the 
blessing of the goitrous pair. Which things are a 
parable. 

Some sneer at eugenics as obtruding into the 
sanctity of human relationships the counsels of 
the farm-yard ; but reflection will show that the 
sanctity 1s heightened, not lessened, when the 
solemn eugenic issues are realised. 

It must be borne in mind that the organism is a 
unity and that the eugenic ideal is much more than 
what 1s commonly meant by the “fine animal.” 
It never occurred to Sir Francis Galton to separate 
the physical from the psychical aspect. His 
famous definition was “ National Eugenics is the 
study of agencies under social control that may 
improve or impair the racial qualities of future 
generations either physically or mentally.” And 
while the eugenic ideal may for scientific purposes 
be spoken of as distinct from those of improved 
function and improved environment, the three are 
practically inseparable. Secure progress depends 
on a combination of the eugenic, eutechnic, and 
euthenic ideals, the deep reason for this being that 
what is good in the inheritance requires an appro- 
priate nurture if 1t 1s to develop fully, that what is 
bad in the inheritance can be to some extent kept 
latent if it find little in the way of appropriate 


SELECTION: ORGANIC AND SOCIAL 247 


liberating stimulus, that the positive steps in the 
direction of eugenic advance come, it seems, from 
germinal experiments and not from individual 
endeavour, from inborn inspiration and not from 
individual thrift, and that, for all we know, the 
improvements of function and environment may 
act as trigger-pulling variational stimuli. In any 
case, a promiseful variation has most chance 
of development and survival if it find itself in a 
progressively evolving nurture. 

To give a practical edge to the discussion, we 
venture to say that whether we have celibate 
fellowships at the colleges, or advertise for a gar- 
dener “‘ without encumbrances,” or dismiss women 
teachers on marriage, or refrain from marrying till 
we have ten times the income our father had when 
he begat us—the list can be continued ad nauseam 
—we are ignoring the fundamental laws of good 
breeding or eugenics, just as we are when we 
refrain from condemning the marriage of the feeble- 
minded or from protesting against certain charit- 
able devices which create more misery than they 
relieve. 

By way of illustration, let us think for a moment 
of China—a country of extraordinary interest 
to the biologist. For four thousand years—until 
1912—it kept up a continuity of state organisation 
and culture; the people have big brains and mar- 
vellous physique ; they are very fertile, the aris- 
tocracy not less than the unlearned; they have 
genuine old families, going back to Confucius, and 
not decadent; they are in many ways very moral ; 
and so on. 

Now there are many reasons for all this, but 
two strike the biologist: (1) To an extent quite 


248 DARWINISM AND HUMAN LIFE 


impossible for us, the Chinese allow natural selec- 
tion in famine and disease, etc., to go on with- 
out hindrance. Here we cannot imitate them. 
(2) For thousands of years, on the other hand, 
the Chinese have paid great attention to breeding, 
to family histories, to family life, to family feeling, 
and honour of ancestry. Ages ago they used to 
send a policeman to eligible bachelors with a notice 
to marry. In their positive eugenic practices the 
Chinese are worthy of our imitation. 

And what is the conclusion of all this talk ¢ 
Nothing new. More and more our human societies 
free themselves from natural selection, and it 
behoves us to make sure that some rational win- 
nowing takes the place of the automatic process 
of nature. There are many processes of social 
selection going on, some for evil and some for good. 
They require to be sternly criticised, especially 
as those that are for good do not seem to be 
getting any grip of the organic qualities of the 
breed. 

The first edition of this book ended with the 
following sentence: “‘ We must take more thought 
of the improvement of our breed, not only for its 
own sake—for healthfulness is as fundamental as 
virtue 1s supreme—but also lest we become in- 
volved in some terrible inter-societary struggle, and 
find—like Samson—when we arise and go out and 
shake ourselves, as at other times before, that our 
strength has gone from us in our sleep.” But 
we would not end on this note now, though the 
fates of the nations still tremble in the balance, for 
enough has been already done to show that the 
British race at home and abroad has lost none of 
its old virtue, and is as strong as ever to fight and 


SELECTION: ORGANIC AND SOCIAL 249 


to endure. Rather would we end with the words 
of one of our poets: 


More glorious hour she has not known: 
A Friend sent forth the call— 
“ Give help, lest we be overthrown ! 
Keep watch and ward in every zone ! ”— 
In mankind’s quarrel and her own 
She shall not faint nor fall. 


When England sheathes her sword again, 
Off shelving shore and scar, 
’Neath foreign field and ocean plain 
Yet more shall be her deathless slain— 
But not in vain, but not in vain 
Shall England go to War! 





REPRESENTATIVE BOOKS ON 
DARWINISM 


251 





REPRESENTATIVE BOOKS ON DARWINISM 


CHAPTER I 


ALLEN, GRANT: ‘‘ Charles Darwin.” 3rd Edition. London, 1886. 

Bettany, G. T.: ‘Charles Darwin.’ London, 1886. 

Butter, SamueL: ‘“ Evolution: Old and New.” 2nd Edition. 
London, 1882. ‘Life and Habit,” 1878. ‘“‘ Luck or 
Cunning,” 1887. 

DaRwWIn, CHARLES: “ His Life told in an Autobiographical Chapter, 
and in a Selected Series of his Published Letters,”” Edited 
by his son, Francis Darwin. London, 1902, 

—— “Life and Letters.” Edited by his son, Francis Darwin. 
3 vols. London, 1887. 

—— ‘More Letters of Charles Darwin.” Edited by Francis 
Darwin and A. C. Seward. 2 vols. London, 1903. 

“The Darwin-Wallace Celebration.” Linnean Society of London, 
1908. 

DreescH, Hans: “Science and Philosophy of the Organism.” 
2 vols. London, 1908. 

Franch, R. H.: “ Der heutige Stand der Darwinschen Fragen.” 
Leipzig, 1907. 

GrEDDES, P., and THomson, J. ArtHuUR: “ Evolution.”’ Williams 
& Norgate: London, 1911, 

Harcket, Ernst: “Generelle Morphologie.” 2 vols. Berlin, 
1866. 

—— ‘ Natural History of Creation.” London, 1879. 9th German 
Edition, Berlin, 1898. 

Hartmann, E. von: “ Wahrheit und Irrthum im Darwinismus.” 
Jena, 1892. 

Howper, C. F.: “Charles Darwin: His Life and Work.” New 
York, 1891. 

Keuioaa, V. L.: ‘“ Darwinism To-day.” Holt: New York, 1907. 

Locy, W. A.: “ Biology and its Makers.” New York, 1908. 

Lotsy, J. P.: ‘ Vorlesungen iiber Descendenz-theorien.” 2 vols, 
Fischer: Jena, 1906. 

253 


254 REPRESENTATIVE BOOKS ON DARWINISM 


MarsHati, A. Mitnes: “Lectures on the Darwinian Theory.” 
Nutt: London, 1894. 

Osporn, H. F.: “ From the Greeks to Darwin.” Macmillan Co. : 
New York, 1895. 


Pauty, A.: ‘‘ Wahres und Falsches an Darwin’s Lehre.” Rein- 
hardt: Miinchen, 1902. 

Romangss, G. J.: ‘‘ Darwin and After Darwin.”’ 3 vols. London, 
1892-7. 


ScuneiperR, K. C.: “ Einfiithrung in die Descendenz-theorie.” 
Fischer: Jena, 1906. 

Sgrpiitz, G.: ‘‘ Die Darwinsche Theorie.”’ 2nd Edition. Leipzig, 
1875. 

Srwarp, A. C. (Editor): ‘ Darwin and Modern Science.” Cam- 
bridge, 1909. 

WaLuLAcr, ALFRED RussgeL: “ Darwinism.’ Macmillan: London. 
1889. 

Wiaeanpn, A.: “ Der Darwinismus und die Naturforschung Newtons 
und Cuviers.” 3 vols. Braunschweig, 1874-7. 

Zi1EGLER, H. E.: ‘‘ Ueber den derzeitigen Stand der Descendenzlehre 
in der Zoologie.”” Fischer: Jena, 1902. 


CHAPTER II 


Bares, H. W.: ‘‘ The Naturalist on the Amazons.” 5th Edition. 
London, 1884. 

Darwin, CHARLES: “The Formation of Vegetable Mould through 
the Action of Worms,” ‘“‘Insectivorous Plants.” ‘ Na- 
turalist’s Voyage.” “ Origin of Species.” 

Frrreirre, Emite: ‘‘ Le Darwinisme.” Alcan, Paris. 

Gave, SzeLina: “ The Great World’s Farm.” Seeley: London, 1893. 

GEDpDES, Patrick: ‘Chapters in Modern Botany.” Murray: 
London, 1893. 

JORDAN, D. 8., and Kenitoaa, V. L.: “ Evolution and Animal 
Life.’ New York, 1907. 

Kerner: “ Natural History of Plants.” Vol. i. 


Mittipr, Hermann: “ Fertilisation of Flowers.’ London, 1883. 
STERNE, Carus: “ Werden und Vergehen.” 3rd Edition. Berlin; 
1886. 


THomson, J. AntHuR: “The Study of Animal Life.” 
London, 1890. Rev:sed Edition, 1916. 

—— “The Biology of the Seasons.” Melrose: London, 1911. 

“The Wonder of Life.’ Melrose: London, 1914. 

Watuace, A. R.: “Island Life.”’ London, 1880. 

Wuitz, GILBERT: “ Natural History of Selborne.” 1788. 


Murray : 





REPRESENTATIVE BOOKS ON DARWINISM 255 


CHAPTER III 


Barttey, L. H.: ‘‘ The Survival of the Unlike.” London, 1896. 
Cor, C. C.: ‘“‘ Nature versus Natural Selection.”? London, 1895, 
Copz, E. D.: ‘The Origin of the Fittest.” London, 1887. 
Cresson, A.: “‘ L’Espéce et son Serviteur.” Paris, 1913. 


DaRWIN, CHARLES: “Origin of Species.” “Climbing Plants.” 
‘** Power of Movement in Plants.” 

Esprnas, A.: ‘“* Des Sociétés Animales.”’ Paris, 1877. 

Girop, P.: ‘ Les Sociétés chez les Animaux.” Paris, 1890. 


Groos, R.: “The Play of Animals.’ London, 1900. 

Heap.ey, F. W.: “ Life and Evolution.” 

—— “Problems of Evolution.” Duckworth: London, 1900. 

Houxuey, T. H.: “ The Struggle for Existence.” Collected Essays. 

KropotTxkin, P.: ‘“‘ Mutual Aid a Factor of Evolution.” Heine- 
mann: London, 1902. 

Wauwace, A. R.: “ Darwinism.” London, 1889. 


CHAPTER IV 
VARIATIONS, MUTATIONS, ETC. 


Battey, L. H.: “ Plant-breeding.” 38rd Edition. New York, 
1904. 

Batreson, W.: “Materials for the Study of Variation.” Mac- 

millan: London, 1894. 

‘“* Problems of Genetics.”” London, 1913. 

Beroeson, H.: “ L’Evolution Créatrice.” Paris, 1907. Trans., 
London, 1911. 

CorzE, E. D.: “The Primary Factors of Organic Evolution.” 
Chicago, 1896. 

DARWIN, CHARLES: “ Variation of Animals and Plants under 
Domestication.””> Murray: London, 1868. . 

Ermer, G. H. Th.: “‘ Organic Evolution.” 'Trans., London, 1890. 

Geppgs, P., and Tuomson, J. Artuur: ‘ The Evolution of Sex.” 
‘Contemp. Sci. Ser.”” Scott: London, 1889. 

Lock, R. H.: ‘‘ Recent Progress in the Study of Variation, Heredity, 
and Evolution.’ Murray: London, 1908. 

Moraan, T. H.: ‘‘ Experimental Zoology.” Macmillan Co.: New 
York, 1907. 

Naaett, C. von: ‘‘ Mechanisch-physiologische Theorie der Abstam- 
mungslehre.”” Miinchen, 1884. 

Semper, K.: “‘ The Natural Conditions of Existence as they affect 
Animal Life.” Kegan Paul: London, 1881. 





256 REPRESENTATIVE BOOKS ON DARWINISM 


Variany, H. pe: “Experimental Evolution.” Macmillan: 
London, 1892. 

VERNON, H. M.: “ Variation in Animals and Plants.” ‘‘ Internat. 
Sci. Ser.” Kegan Paul: London, 1903. 

Vrizs, H. pe: “ Die Mutations-theorie.” 2 vols. Veit: Leipzig, 
1901, 1903. ‘Trans., London, 1910, 1911. 

—— “Species and Varieties, their Origin by Mutation.” Chicago, 
1905. 

ZinGLER, H. E.: “‘ Ueber den derzeitigen Stand der Descendenzlehre 
in der Zoologie.” Fischer: Jena, 1902. 


CHAPTER V 
HEREDITY 


Batuson, W.: ‘ Mendel’s Principles of Heredity.” Cambridge, 
1909. 

—— ‘The Methods and Scope of Genetics.” Cambridge, 1908. 

‘Problems of Genetics.’”? London, 1913. 

Brooks, W. K.: ‘ The Foundations of Zoology.” Macmillan Co.: 
New York, 1898. 

CasTLE, W.: ‘‘ Heredity.”” New York, 1912. 

ConkKLIN, E. G.: “ Heredity and Environment in the Development 
of Men.” Princeton, 1915. 

Corr, E. D.: ‘The Primary Factors of Organic Evolution.” 
Chicago, 1896. 

CorREns, C.: ‘‘ Ueber Vererbungsgesetze.” Borntraiger: Berlin, 
1905. 

DarpisHirE, A. D.: ‘“‘ Breeding and the Mendelian Discovery.” 
Cassell: London, 1911. 

DaRWIN, CHARLES: ‘Variation of Animals and Plants under 
Domestication.””> Murray: London, 1868, 

Dexace, Yves: “ L’hérédité.” 2nd Edition. Paris, 1903. 

Denpy, ARTHUR: “Outlines of Evolutionary Biology.” London, 
1912. 

DonoastER, L.: ‘ Heredity.” Cambridge, 1910. 

Exuis, Havetock: “ The Task of Social Hygiene.” London, 1912. 

Ewart, J. C.: “The Penycuik Experiments.”’ Edinburgh, 1899. 

GALTON, Francis: ‘‘ Natural Inheritance.’”’ Macmillan: London, 
1889, 

GiaRD, A.: ‘‘ Controverses Transformistes.”” Naud: Paris, 1904. 

Hutton, F. W.: “ Darwinism and Lamarckism.’’ London, 1899. 

JOHANNSEN, W.: ‘ Elemente der exakten Erblichkeitslehre. 2nd 
Edition, Jena, 1913. 





REPRESENTATIVE BOOKS ON DARWINISM 257 


More@an, C. Luoyp: “ Habit and Instinct.” Arnold: London, 
1896. 

Morean, T. H.: ‘‘ Heredity and Sex.” New York, 1913. 

Pauty, A.: ‘“ Darwinismus und Lamarckismus.” Reinhardt: 
Miinchen, 1905. 

Punnett, R. C.: “ Mendelism.” Cambridge. 2nd Edition, 1905. 

Rep, G. ARCHDALL: “ Principles of Heredity.” Chapman & Hall: 
London, 1905. 

RicNAno, E.: “ Ueber die Vererbung erworbener Eigenschaften.” 
Engelmann: Leipzig, 1907. 

Sremon, R.: ‘“‘ Die Mneme als erhaltendes Princip im Wechsel des 
Organischen Geschehens.” Engelmann: Leipzig, 1904. 

Spencer, Herpert: “ Principles of Biology.” Williams & Nor- 
gate: London, 1866-8. 2 vols. Revised Edition, 1898. 

THomson, J. Antuur: “ Heredity.” Murray: London, 2nd Ed., 
1912, 

Wuismann, Aucust: “The Germ-plasm.” ‘Contemp. Sci. Ser.” 
Scott: London, 1893. 

—— “ Essays on Heredity and Kindred Subjects.” Oxford, 1891-2, 

Witson, E. B.: ‘ The Cell in Development and in Inheritance.” 
2nd Edition. Macmillan: London, 1900. 

Zinciir, H. E.: “ Die Vererbungslehre in der Biologie. 
Jena, 19085. 


33 


Fischer ; 


CHAPTER VI 
SELECTION, ORGANIC AND SOCIAL 


Ammon, O.: Die natiirliche Auslese beim Menschen.” Fischer: 
Jena, 1893. 

—— “Der Abanderungsspielraum.” Diimmler: Berlin, 1896. 

BALDWIN, J. Mark: ‘‘ Development and Evolution.” New York, 
1902. 

Cox, C. C.: “Nature versus Natural Selection.” London, 1895. 

Darwin, CHaRLEs: “ Origin of Species.” Murray: London, 1859, 

—— “Descent of Man.” Murray: London, 1871. 

Geppkgs, P., and Tuomson, J. AntHuR: “ The Evolution of Sex.” 
1889, Revised Ed. 1901. 


—— —— “Sex.” Williams & Norgate: 1914. 
Gutiox, J. T.: ‘‘ Evolution, Racial and Habitudinal.” Washing- 
ton, 1905. 


Heaptey, F. W.: ‘Life and Evolution.” ‘“‘ Problems of Evolu- 
tion.” London, 1900. 
17 


258 REPRESENTATIVE BOOKS ON DARWINISM 


JoRDAN, D.S.: “ Footnotes to Evolution.” New York, 1898. 

‘The Human Harvest.” Boston, 1907. 

Kexuer, A. G.: Societal Evolution: A Study of the Evolutionary 
Basis of the Science of Society. Macmillan Co.: New 
York, 1915. 

Lanxestier, E. Ray: ‘The Kingdom of Man.” London, 1907. 

McDoveatt, W.: “An Introduction to Social Psychology.” 
London, 1908. 

MiTcHELL, P. CHatmMEeRs: “ Evolution and the War.” Murray: 
London, 1915. 

Moraan, T. H.: “ Evolution and Adaptation.” Macmillan Co. : 
New York, 1903. 

Prarson, Karu: ‘‘The Chances of Death.” 2 vols. Arnold: 
London, 1897. ‘‘ The Grammar of Science.” 2nd Edition. 
Black: London, 1900. ‘‘ National Life from the Stand- 
point of Science.” ~London, 1901. 

PiaTe, L.: “Selektionsprinzip und Probleme der Artbildung. 
Kin Handbuch des Darwinismus.” 3rd Edition. Engel- 
mann: Leipzig, 1908. 

Poutton, E. B.: “Charles Darwin and the Theory of Natural 
Selection.” London, 1896. “‘ Essays on Evolution.” 
London, 1908. 

Pycrart, W. P.: “ The Courtship of Animals.”? London, 1913. 

SALEEBY, C. W.: ‘‘ Parenthood and Race Culture.” London, 1909. 





SpenceR, Herpert: ‘The Inadequacy of Natural Selection.”’ 
London, 1893. 
WALLACE, ALFRED RussEL: “Contributions to the Theory of 


Natural Selection.” Macmillan: London, 1890. 
Weismann, Aveust: “ The Evolution Theory.”” 2 vols. Arnold: 
London, 1904. 
Wo.rr, E.: “ Beitraége zur Kritik der Darwinschen Lehre.” Leip- 
zig, 1898, 


INDEX 


A 


Acquired characters, 118; de- 
fined, 157; transmission of, 
157. See also Modifications 

Adaptations, 114, 194 

Adherence to type, 23 

Alcoholic poisoning, 172 

Allen, Dr. E. J., 50 

Allen, Mr. J. A., 100, 102 

Alpine plants, 160 

Ancestral Inheritance, Galton’s 
Law of, 143 

Andalusian Fowls, 151 

Anthropomorphism of idea of 
struggle, 70 

Aosta, 246 

Aphides, increase of, 82 

Archeopteryx, 24 

Arctic animals, 191 


B 


Bacon, 32, 34, 184 

Balance of nature, 64 

Baldwin, Prof. Mark, 119, 169 

Balfour, Mr. Arthur, 40 

Basset hounds, 144 

Bateson, 30, 100, 101, 105, 136, 
155 

Beagle, Voyage of the, 5, 40 

Beebe, C. W., 122 

Bergson, 21 

Biffen, experiments on immun- 
ity from rust, 245 

Biometrika, 101 

Blending, 145 

Brooks, Prof. W. K., 33 





Browne, Sir Thomas, 176 

Buckle, “‘ History of Civilisa- 
tion,’’ 39 

Buffon, 19 

Bullen, Mr. G. E., 50 

Bumpus, Prof., 201 

Burbank, 194 

Bury, 226 

Butler, Samuel, 18, 38, 169 


Cc 


| Cannibalism in the cradle, 12 


Castle, W. E., 135, 150 

Cats and clover, 52 

Cause, different kinds of, 2] 

Caution, necessity for scientific, 
32 

Cesnola, 199 

Chambers, Robert, 37 

Chemical changes in sea-water, 
effects of, 121 

China, eugenics in, 247 

Chromosomes, 138 

Civilisation, dilemma of, 218 

Cold, effect of, on growth, 122 

Combats of rival males, 208 

Continuity of generations, 132 

Co-operation, 90 

Correlation of organs, 46 

Correns, Prof., 135 

Coulter, Prof. J. M., 204, 205 

Crampton, Prof. H. E., 29, 81, 
202 

Creationist view, 19 

Cretinism, 245 

Criminals, 245 

Cross-fertilisation, 51 


259 


260 
D 


Dakin, W. J., 50 

Darwin, biographical notes, 3; 
published works, 5, 6; mani- 
foldness of his services, 9; his 
position in regard to struggle 
for existence, 86 ; to selection, 
184; on war, 229 

Darwin, Erasmus, 4, 19 

Darwin, Robert Waring, 4 

Davenport, 191 

Davenport, Prof. and Mrs., 155 

Deep sea, nutritive chains in, 51 

Dependence on surroundings, 47 

Descent and Ascent of Man, 28 

Descent, doctrine of, 18, 22 

Determinant, in inheritance, 144 

Discontinuous variation, 105 

Disease, transmissibility of, 162 

Domesticated animals, mutation 
in, 108 

Domestication and variability, 
14, 108 

Dominants, 148 

Drinkwater, 155 

Drummond on termites, 59 

Dysgenics of war, 228 


E 


Earthworms, 56; Darwin’s book 
on, 6, 33, 58 

Elimination, discriminate, 84, 
199; indiscriminate, 83 

Endeavour after well-being, 169 

Engelmann, 197 

Environment, changes of, as a 
cause of struggle, 82; and 
function, 168 

Error, curve of frequency of, 102 

Escherich, Prof., on termites, 
59, 60 

Eugenic selection, 242 

Eugenics, 240, 246 

Eutechnics, 240 

Eutopias, 240 

Evening Primrose, 106 

Evolution formula and gravita- 
tion formula, 26 


INDEX 


Evolution idea, 17 

Evolution of sex, 104 

Evolution theory a modal inter- 
pretation, 19; evolution, raw 
materials of, 97-126 

Ewart, Prof. Cossar, experiments 
on hybridisation, 147 

Exclusive inheritance, 146 

Experimental study of heredity, 
145 

Extermination, consequences of, 
64 

Eyes, colour of, 135 


F 


Factor, in inheritance, 144 
Farabee, 155 

Faraday, 33 

Fate, struggle with, 13 
Fellows, struggle with, 12 
Ferriére, Emile, 27 

Filial Regression, 139 
Fixity of species, 19 
Fluctuations, 158 

Foes, struggle with, 13 
Forests, destruction of, 62 
Foster, Sir Michael, 32 
Friedenthal’s test, 28 


G 


Gager, C. S., 116 

Galapagos Islands, fauna of, 5 

Galton, 4, 30, 105, 131, 132, 139, 
141, 240 

Gamete, 152 

Gammarus, 121 

Geddes, Prof. Patrick, 183, 205, 
240 

Geikie, Sir Archibald, 31 

Gene, in inheritance, 144 

Geographical distribution, 25 

Geological record, 24 

Germ-cells, microscopical study 
Ol not 

Germ-plasm, continuity of, 132 

Germinal selection, 113 

Gill-slits, 25 

Goethe, 19 


INDEX 


Grand’Eury, 204 
Guinea-worm and cyclops, 55 
Gulick, 211, 212 


H 


Hall, Prof. Stanley, 29 

Haycraft, Prof. Berry, 220 

Healthful occupations, 241 

Heine, 176 

Henslow, 5 

Heraclitus, 49 

Heredity = the genetic continu- 
ity between successive genera- 
tions, 131 ; methods of study- | 
ing, 136 

Herschel, 102 

Homology of forelimbs of verte- 
brates, 23 

Hormones, 163 

Housefly, 82 

Hudson, W. H., 78, 79, 89 

Human life, relation of, to muta- 
tion, 123 

Human race and animal world, 
contrast between, 214 

Hurst, 156 

Huxley, 33, 37, 38, 41, 48, 139 





I 


Increase, rate of, 82 
Infection of offspring 

birth, 160 
Inheritance, facts of, 129-177 
Intelligence, liberation of, 29 
Interrelations, 35, 45-65 
Isolation, 210 





before 


J 


James, William, 233 
Jenkin, Prof. Fleeming, 99 
Jordan, 211, 212, 225, 227 


K 


Kammerer, experiments with 
salamanders, 164 
Keller, 216 


261 


Kellicott, 85 
Kipling, 90 
Kropotkin, 89, 91 


L 


Laissez-faire position, 219 

Lamarck, 19, 22, 99 

Lamarckian view of transmissi- 
bility of acquired characters, 
119, 120 

Lankester, Sir E. Ray, 71, 205, 


218 
‘‘ Law of Parsimony,” 167 


Lemmings, march of, 81 
Leptinotarsa, variations in, 115 


| Loeb, 122 


Lucas, A. H. S., 63 


| Lucas, Prosper, 130, 140 


Lyell, 5 


M 


MacDougal, D. T., 116 

Macfie, R. C., 81 

Macgillivray, 91 

Mackerel and sunlight, 50 

Madeira insects, 190 

Malthus, 71, 181 

Marchal, 122 

Marshall, Prof. A. Milnes, 25, 59 

Mendel, 136 

Mendelian inheritance, 148, 154 

Mendelism, 107, 135; practical 
importance of, 155 

Mendel’s Law and Galton’s Law, 
157 

Meredith, 93 

Mitchell, Chalmers, 74, 216, 234 

Mivart, 109 

Modifications, 118; indirect im- 
portance of, 119, 169 ; second- 
ary effects of, 161; transmis- 
sibility of, 157 

Mongoose in Jamaica, 65 

Moral character, inheritance of, 
175 

Morgan, Prof. Lloyd, 119, 126, 
169, 210 

Morgan, T. H., 31 


262 

Mouse, sand-coloured variety of, 
17 

Mud and clear thinking, 49 

Miiller, Fritz, Facts for Darwin, 
25 

Mutation, Darwin’s position in 
regard to, 108; theory of, 106 

Mutations of Evening Primrose, 
22, 106 

Mutual aid, Kropotkin on, 89 


N 

Niageli, 160 

Napoleon, effects of his wars, 227 

Natural selection, 15 ; the theory 
of stated, 187; illustrations of 
the theory of, 190 ; objections 
to the theory of, 192; evi- 
dences of, 198; efficacy of, 
201; in human life, 213 

Naturalist’s problems formula- 
ted, 6-9 

** Nature,’’ 173, 176 

** Nature ’’ and ‘“‘ Nurture,’’ dis- 
tinction between, 131 

Neo-Darwinians, 167 

Neo-Lamarckians, 166 

Nettleship, 155 

Night-blindness, 155 

“Nurture,” 131, 171, 174, 176 

Nutritive chains, 48 


O 


Organic progress, 97 

Organisms, correlation of, 45; 
interdependence of, for con- 

' tinuance of species, 51 

** Origin of Species,’’ 37, 98 

Osborn, H. F., 119, 129, 169, 206 


P 


Pairing of similar pure-bred 
forms, 145 

Paleontology, 206 

Paludina, 25 

Pangenesis, Darwin’s idea of, 163 

Parasites, life-histories of, 55 

Parasitism, 93 


INDEX 


Parthenogenesis, artificial, 121 

Particulate inheritance, 146 

Pearson, Prof. Karl, 33, 36, 130, 
143, 217, 242, 244 

Peckham, Prof. and Mrs., 209 

Peridinide, 50 

Phenacodus, 24 

Pigeons, inheritance in, 
variation in, 185 

Planorbis, 25 

Plasticity, individual, 121; of 
organism, 170, 173 

Plate, 86 

Plato, 219 

Play, 125 

Poulton, Prof. E. B., 72, 83, 122, 
132, 197, 199 

Problems of the Naturalist, 6 

Przibram, Dr., 138 

Punnett on Mendelism, 136, 151 


147; 


Q 
Quetelet, 102 


R 


Rabbits, 147 

Rats, brown versus black, 74 

Recapitulation theory, 25 

Recessive characters, 148 

Regeneration of lost parts, 195 

Regression, 139 

Reproductive selection, 188 

Reversed selection in human 
society, 224 

Reversion, 134, 147 

Romanes, 35, 161, 211 

Rudimentary organs, 23 

Russell, E. §8., 188, 202 


S 


Salamanders, 165 

Saleeby, 218 

Sandeman, G., on military spirit, 
228 

Sanders, 199 

Scientific mood, ideals of, 31; 
characteristics of, 32 

Seeck, 226 


INDEX 


Seeds, scattering of, 53 

Segregation of factors, 153 

Selection and stimulus, 168 ; or- 
ganic and social, 181-249; 
periodic, 200 ; sexual, 207; in 
human society, 213; social 
and natural, 217. See Natural 
Selection 

Seeley, 226 

Semon, experiments with aca- 
cias, 171 

Silvestri, 60 

Social surgery, 221 

Spencer, 88, 159, 163, 170, 183, 
218; and Darwin, 71 

Sprengel, Christian Conrad, 52 

Squirrels and wood-pigeons, 62 

Staples-Browne, 147 

Statistical study of heredity, 139 

Stature, 227 

Stevenson, R. L., 76 

Stockard, 121 

Strasburger, 134 

Struggle for existence, 11, 13, 69- 
94; between fellows, 73; be- 
tween foes, 74; with fate, 75; 
among plants, 75; reasons for, 
80 ; results of, 83; Darwin’s 
conception of, 86; conception 
of, applied to human life, 92 

Survival of the fittest, 224 


T 


Tennyson, 12, 70 

Termites, 59 

Tierra del Fuego, 5 

Tower, Prof., 115 

Transilient variations, 158 

Transmissibility of acquired cha- 
racters, 157, 176 

Transmission in unicellular or- 
ganisms, 160 

Tredgold, 244 

Treviranus, 19 

Trotting horses, 159 


263 


Tschermak, 135 
Tse-tse flies, 55 


U 
Unit characters, 135, 150 


Vv 


Variability of living creatures, 
14; a fact of life, 15; a con- 
dition of organic progress, 95 

Variational stimuli, 114 

Variations, abundance of, 101; 
causes of inborn, 15; correla- 
tion of, 103; discontinuous, 
105; origin of, 110; propor- 
tion between frequency and 
amount of, 102 

Vestigial organs, 23 

Vries, H. de, 22, 105, 106, 135 


W 


Wagner, 211 

Wallace, A. R., 15, 103, 182, 
208; and Darwin, 17, 183, 185 

Waltzing mice, 153 

War, 225-39 

Web of life, 10, 45-65, 193; 
practical importance of realis- 
ing it, 61 

Wedgwood, Josiah, 4 

Weismann, 72, 85, 112, 
133, 196, 207, 208, 210 

Weldon, experiments on shore- 
crabs, 200 

Wenley, R. M., 38, 41 

White, Gilbert, on earthworms, 
56 

Whymper, 245 

Wilde, Norman, 89 

Wilson, E. B., 164 


113, 


Z 


Zeiller, 204 
Zygote, 152 










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